Halacha: Overview

See also >> FAQs (Halacha) / The Analogy / How Does it Work? / How to Use? / Responsa / Endorsements


Jump to >>  Maris Ayin / Muktzah / Pesik Reisha & Miskaven / Zilzul Shabbos & Spirit of Shabbos / Hergelei Issur & Uvdin d’Chol / Bal Tashchis


(Note that we are not qualified to take any Halachic position on any matter.  Halachic information presented is based upon the opinions and feedback of independent rabbis & poskim.)


We realize that KosherSwitch® technology is revolutionary and paradigm-shifting, and recognize that we will encounter two types of users within our population.  The first simply wants to know “who endorses it?” and that’s good enough for them.  The other is more inquisitive and wants to know “how does it work?” and “why is its use permitted?”  We strive to accommodate both ideologies, working hard to educate everyone within the framework that they are interested. We encourage every user – even those who are not yet comfortable to become users – to learn more, discuss it with their local rabbi or mentors, and ask questions.  We recognize that not everyone will flock to KosherSwitch® on day one, but through education, we believe that we can minimize the polarizing effects of our technology and help bring many of its benefits to the masses.


Confirming the technology’s Halachic feasibility has always been one of our prime objectives. We have spent the last few years actively consulting with some of the world’s leading rabbis, poskim, and Torah minds, and many of them have endorsed our technology and encouraged us to pursue our vision.  Throughout our journey, we have been fortunate to acquire many Halachic insights regarding the permissibility of KosherSwitch®, and have presented these throughout our website.  However, since much of the Halachic literature acquired is highly technical and is written in Hebrew, we present a synopsis of the relevant issues below.  We stress that these are only digests, and encourage users to reference the original rabbinical documents available on our website.  This section assumes familiarity with the technology, how it is used, and how it works.


Maris Ayin

(Giving onlookers the impression that one is doing something that is prohibited)


There are a number of factors that alleviate any concerns that use of a KosherSwitch® may lead to Mar’is Ayin. While the information below is proof-positive for the vast majority of readers, those who still find it difficult to visualize are encouraged to witness an actual KosherSwitch® Classic in action.  The tangible is obviously more convincing than the abstract.


First, we must understand that the issue of Mar’is Ayin only relates to when one is actually flicking the KosherSwitch® on/off button.  There is no issue of Mar’is Ayin when one sees lights turning on/off from outside, since the assumption is that a traditional and permissible method was used (i.e., a Shabbos clock/timer or a Shabbos Goy).


It’s impossible for one’s usage of a KosherSwitch® to be mistaken for a regular light switch.  The KosherSwitch® has been custom engineered to look completely different from any other switch available in the market.  It is designed with several Halachically-significant heikers (distinguishing factors):


  • It looks nothing like the rocker-type (“Decora”) or classic toggle-type switch, which together make up over 99% of the switches installed in the USA.
  • It is clearly marked with the KosherSwitch® brand/logo, etched into the plastic of the Mode Selection door.
  • It contains a unique Status Light which provides several critical distinctive elements: 1) The fact that it’s there, as a cutout in the front cover, and in perfect line-of-sight of the user is itself unique. 2) In Normal Mode, it’s always off, while in its Sabbath Mode it’s always on. 3) In its Sabbath Mode, the Status Light is constantly cycling between green and red, every few seconds.
  • The very presence of a Mode Selection door is an important heiker over the vast majority of classic wall switches.  Other devices that contain such a door represent a small percentage of a tiny fraction of all switches, and do not contain the other elements present in the KosherSwitch® Classic, such as the sliding on/off button or Status Light.
  • An On/Off button that looks like it will slide up or down, but in fact, it moves into its on or off positions with unique tactile resistance and a “snap”.
  • When the Mode Selector door is open, there are many markings indicating that this is a special kind of switch, and a Mode Selector button to choose between a Sabbath Mode and Normal Mode.

Perhaps most importantly, the switch functions and behaves very differently than a regular switch (and from itself when it’s in Normal Mode).  Here’s what one would witness if they were watching someone using a KosherSwitch® on Shabbat or Yom Tov: 1) He walks up to a switch; 2) looks or waits for something (he’s actually looking for a green Status Light or waiting for it to turn from red to green); 3) flicks the switch “on”; 4) nothing happens (guaranteed); 5) some time later (unknown exactly how long because of uncertainty from safeiks), the attached fixture turns on.  The onlooker either knows this is a KosherSwitch® or will ask, “hey, what were you doing, and why isn’t the room light switching on?”  By definition, this cannot be classified as  Mar’is Ayin.


Incidentally, this point is vitally important in eliminating confusion for the users themselves, as opposed to onlookers.  The way that the KosherSwitch® Classic “behaves” in Normal Mode is pointedly different than in its Sabbath Mode.  Accordingly, users’ interactions will also be markedly different.  In its Normal Mode, the above scenario would be identical to using a traditional light switch: 1) He walks up to a switch; 2) flicks the switch “on”; 3) attached fixture turns on “instantly.”  In Normal Mode, he doesn’t even look at the switch, whereas in Sabbath Mode, he must look for a green Status Light and determine if it’s “safe to use” before even touching the on/off button.


The heiker (distinguishing factors) in the KosherSwitch® are similar to many instances in Halacha where Mar’is Ayin would normally be an issue, but with the proper heiker, the issue is eliminated.  An example is drinking almond “milk” while enjoying a steak, as long as the almond peels are placed next to the cup (or in more modern terms, soy milk while leaving the container on the table).  Additionally, as KosherSwitch® gains traction and acceptance, it will be widely known that such a capability exists, thereby avoiding the misconception of Mar’is Ayin altogether.


(See KosherSwitch® Responsa, Section 7)


(Items that are “set aside” from before Shabbat because of their prohibited nature)


The laws of muktzah do not apply to KosherSwitch® for a very simple reason: Once we establish that its use it permitted, by definition, it cannot be considered muktzah! Additionally, there are many opinions that rule that the laws of muktzah do not apply in cases of mechubar (an item that’s secured to a stationary object or the ground).


(See KosherSwitch® Responsa, Section 14; HaGaon R’ Bracha Responsa and HaGaon R’ Ben-Chaim Responsa citing HaGaon Maran Ovadia Yosef Responsa shlit’a, Yabia Omer Volume 3, Orach Chaim Siman 18)

Pesik Reisha & Miskaven

(The forbidden side-effect to a permissible action & the intention of one’s actions)


The issue of Pesik Reisha and Miskaven are addressed using different approaches, summarized below:


The isolated obstructing element

Another approach taken by many, including HaGaon R’ Chaim Tzvi Shapiro, is summarized in the conclusion of his responsum:  “In our case [with regard to KosherSwitch], there is no shred of concern that at the time that one opens or closes the blocking vane [the isolated mechanical on/off button] that there will exist a Koach Rishon [primary force], as was analyzed and clarified above.  Therefore, there is absolutely nothing forbidden relating to it, and not even Gram Kibuei [indirectly caused extinguishing], and it is permitted [on Shabbos, l’chatchila] according to all Halachic opinions, as was analyzed and clarified above.”


This approach proves through several often-cited sources in the Gemara, Shulchan Aruch, Rishonim, and Acharonim that deal with whether one may open a window next to a lit candle on Shabbat, and under what conditions this may be done.  The opinions that forbid it do so out of concern that a wind will blow the candle out at the exact time that the window is opened, and it will be considered as if the individual directly extinguished the candle.  However, in the case of KosherSwitch® there are several factors that mitigate this concern.  First, when the Status Light is green, we’re assured that the device is totally dormant or “dead” and that one’s action is solely the movement of a piece of plastic (a guarantee that no “wind” exists when the “window” is opened).  We never interact with the mechabe (the element that’s doing the extinguishing [the light pulse transmitter]) or the mitchabe (that which is being extinguished [the light pulse receiver]).  Additionally, due to the two failure probabilities, there’s absolutely no assurance that a “wind” will blow in the upcoming cycle, and even if it does, that it would succeed in extinguishing the “candle”.


The uncertainty principle

There’s no concern of Pesik Reisha since within each of the device’s cycles, there’s no certainty that the forbidden side-effect will occur as a result of our permissible action.  The laws of Pesik Reisha are only applicable when the forbidden side-effect occurs with absolute certainty.


However, should we be concerned that in our case, where the user intends the fixture attached to the KosherSwitch® to turn on/off, that Pesik Reisha still applies?  No, since the users actions are simply the movement of piece of plastic at a time of insignificance (since the green Status Light indicates that the switch is “dead”). Thus, the movement of the plastic on/off button is associated with the user, whereas the ultimate outcome is not.


What about safeik (uncertain) Pesik Reisha, which some poskim also prohibit?  Such a concern doesn’t apply to our case.  Safeik Pesik Reisha applies to cases in which one is unsure if a given situation that already occurred constitutes a Pesik Reisha or not.  In the case of KosherSwitch®, the uncertainty relates to something that may or may not occur in the future!  This is not considered Safeik Pesik Reisha by any of the poskim.    (See KosherSwitch® Responsa, Section 5)


Still, one can argue that statistically we expect the KosherSwitch® to ultimately trigger in the manner intended!  While statistically this may be true, Halacha does not view it as such, since it views each cycle independently and with uncertainty.


The very definition of Pesik Reisha requires a direct action that brings about the prohibited side-effect with absolute certainty.   KosherSwitch® clearly does not fit within this definition.  (See KosherSwitch® Responsa, Section 6)


(See HaGaon R’ Shapiro Responsa; HaGaon R’ Bracha Responsum citing HaGaon Maran Ovadia Yosef shlit’a Responsa Yabia Omer Volume 7, Orach Chaim Siman 36; HaGaon R’ Ben-Chaim Responsum citing Shemiras Shabbos Kehilchasa Chapter 10, Siman 14, HaGaon Dayan Yisroel Harfenes sources)

Zilzul Shabbos & Spirit of Shabbos

(Denigration of the Sabbath and the proper “Spirit of Shabbat”)


KosherSwitch® mitigates Shabbat desecration (chilul Shabbos) both b’mezid (intentionally) in populations that are not yet shomer Shabbat and b’shogeg (unintentionally) in those that are.  It makes Shabbat more attainable and enjoyable to the masses by removing a massive barrier in a Halachically permissible manner. A positive byproduct of the KosherSwitch® Classic is that once it’s installed, it must be used in either Sabbath or Normal modes. Even in Normal Mode, use of the switch does not constitute Chilul Shabbos with nearly the same severity as a regular switch. By enhancing the observance and enjoyment of Shabbos itself, the KosherSwitch® advances the Spriit of Shabbos.


Interestingly, when Shabbos clocks/timers were first introduced, they were also widely criticized and hardly accepted.  Today, timers are used ubiquitously and are a staple in many Jewish homes.


B’shogeg is still prevented

Many still violate the laws of Shabbat and Yom Tov with respect to electricity on a regular basis b’shogeg (accidentally).  KosherSwitch® eliminates these occurrences.


Additionally, within the Sabbath-observing population, there are many instances when Shabbos clocks/timers are mis-programmed and/or regular switches that have been inappropriately set or used.  Often, these are met with outright Halachic violations, either through an inappropriate amira l’akum (a directive to a Shabbos Goy), through an action that is performed b’shinui (differently than the usual manner), or by encouragement of a minor to rectify the problematic situation.  KosherSwitch® is obviously preferred to these methods.



(See KosherSwitch® Responsa, Sections 7, 9, 12, 13 and various endorsements)

Hergelei Issur & Uvdin d’Chol

(Concerns that one will grow accustomed to using electricity on Shabbat, and will come to use a regular wall switch instead of KosherSwitch®)


Historically, there have been many cases of activities that were forbidden on Shabbat.  However, once a method to perform the activity in a permissible manner was discovered, they have been permitted without any concern for Hergelei Issur.  For example, opening a can on Shabbat by first piercing its bottom; or opening refrigerator door without concern that the light/sensor was not disabled prior to Shabbat.


Regardless, in our case no such concerns exists, since the KosherSwitch® is very different than traditional wall switches, so there’s no direct parallel between the two.  Additionally, the KosherSwitch® is used in very different ways and also behaves differently depending on when it’s used – a Normal Mode during weekdays and a Sabbath Mode during Shabbat and Yom Tov (see also Maris Ayin above).  There is no possibility that using it in one mode will accustom the user to use it in the other, or that by using a KosherSwitch®, one will believe that all switches are permissible.


(See KosherSwitch® Responsa, Sections 8 and 7)

Bal Tashchis

(Unnecessary wastefulness)


Energy conservation and the “green” movement were anticipated centuries ago by the sages of the Talmud.  “Those who burn more fuel than necessary violate the law of Bal Tashchis [unnecessary wastefulness]” (Talmud, Shabbos 67b).  Once we establish that use of KosherSwitch® is permitted, we may argue that those who do not use such devices are in violation of the Torah prohibition of Bal Tashchis.  By allowing fixtures to turn on when needed, and turn off when no longer required, energy waste is dramatically curbed.  The alternatives are timers that stay on much longer than required, or simply leaving a fixture (lights, air conditioners, hotplates, etc.) on for the entire Sabbath or Jewish holiday.


Aside from environmentalism, the financial impact of broad worldwide use of KosherSwitch®-based solutions is colossal, translating to savings in the order of tens of millions of US dollars per year.


(See KosherSwitch® Responsa, Section 11 and various endorsements)



See also >> FAQs (Halacha) / The Analogy / How Does it Work? / How to Use? / Responsa / Endorsements


Jump to >> Intuitive Summary / Maris Ayin / Muktzah / Pesik Reisha & Miskaven / Zilzul Shabbos & Spirit of Shabbos / Hergelei Issur & Uvdin d’Chol / Bal Tashchis


More common questions answered in the FAQs


Is KosherSwitch® meant to be used by everyone?

Due to the highly-relevant nature of this question, and the lack of visibility of the answers when presented in the form of a FAQ, we have relocated the information to a dedicated a page.


Is this real? I get to control electricity on Shabbat? Can it be used l’chatchila or is it only as a b’dieved?

Yes, it is very real!  Many of the rabbis/poskim who have endorsed the technology agree that it is not grama (indirect causation) and is therefore permissible l’chatchila  (the ideal Halachic condition or ab initio) and not just b’dieved (acceptable but not the ideal Halachic condition).  See the Halacha section for further details.

Who says that the technology is permissible/“kosher” to use?

From the early concept days for KosherSwitch®, we have been in constant consultation with many prominent Torah scholars around the world, seeking their guidance and their rulings.  We have always remained mindful of our primary objective of zikuei harabim – bring the merit to the masses.  All of our endorsements are from Orthodox, Haredi, and/or Hassidic rabbis/poskim.  See the Endorsements section for details.

How long does it take for the fixture attached to a KosherSwitch® Classic to turn on/off?

In Normal Mode, it’s instant.  In KosherSwitch® Sabbath Mode, there’s no way to predict how long it will take, since the device must go through one or more cycles, each with a possibility that it will fail to function as intended.  Typically, it will take “dozens of seconds” but sometimes, randomly,  it can take more than a minute or two.

Are the rabbis that endorse the technology engineers? Do they understand electronics?

The concepts and Halachic issues raised by KosherSwitch® technology are not necessarily analyzed by a rabbi/posek  on a technological level.  Instead, they are compared to cases and analogies that exist in the Talmud, the Shulchan Aruch and related works.  For example, rather than dealing with electric circuits, their analysis would examine the permissibility of extinguishing a candle by opening a window at a time when a wind is not yet present, etc.

Isn’t your technology the same as moving the pins on a Shabbos clock/timer?

No.  Among other reasons, the movement of the timer pins more directly cause the triggering of the electrical circuit.  KosherSwitch® is innovative, and quite different.  See the Halacha section for an in-depth analysis.

Isn’t KosherSwitch® just another “grama” (indirect causation) device? How are you any different than Zomet? What’s special about your technology?

No, KosherSwitch® is “un-grama”™ technology based on the rulings of many leading rabbis/poskim.  This is why its use is not limited only to the infirm and other lenient situations, as are the solutions offered by Zomet and the Institute for Science and Halacha.  For more details, see: How Does it Work, Analogy, and Halacha.

When all is said and done, isn’t it my action that’s causing the light to go on or off?

Technically, yes; Halachically, no!  (Actually, your action isn’t causing anything to happen, but only allowing something to maybe happen in an unrelated future.)  Halacha does not only consider the end result, but also carefully evaluates the means used to get to that end. See the Halacha section for an in-depth analysis.

Isn’t KosherSwitch® just like the Star-K/Rabbi Heinemann Sabbath Mode feature?

No, KosherSwitch® is very different.  More details are available here.



Shouldn’t we be concerned that KosherSwitch® technology will be used in inappropriate ways? Won’t it be used as a T.V. remote and to drive a car on Shabbat?!

No, that’s the last thing that we would want to see happen.  Our mission is to enhance the sanctity of Shabbos, not to diminish it.  Someone who is determined to experience Shabbos in inappropriate ways will find a way of doing so with or without our technology.  Therefore, our focus is Zikuei Harabim — to bring the benefits to the masses and not be concerned with individual “renegade” users.

Isn’t this just a loophole that’s bypassing the religious rules? Isn’t this Halachic subterfuge?

No.  Halacha is very specific in what is permitted vs. prohibited.  We have invented a way of doing something that traditionally has been forbidden in a new way that’s permissible and yields tremendous benefits.  Historically, there are many such examples, and they are not viewed as bypassing Halacha.

Isn’t it better to be more stringent and avoid using KosherSwitch® ?

The real question to ask is “which is more stringent – using a KosherSwitch® or not using one?!”  We believe that one is behaving much more stringently by using our technology rather than avoiding it.  Since KosherSwitch® makes chilul Shabbos impossible, it is the perfect tool for one who wishes to be stringent since it will prevent him/her from even accidentally desecrating the Sabbath (or doing so in a Halachically forbidden manner in other extenuating circumstances, such as in amira l’akum).  Still, use of our technology is highly subjective, and we don’t expect everyone to use it.  Existing psychology takes time to reshape, and adoption in certain groups will be slow.  However, we believe that history will prove that by not using a KosherSwitch®, one is being too lenient.


Have any rabbis/poskim that have been approached refused to endorse KosherSwitch® ?

We have spent the last few years securing the responsum & endorsements of many respected rabbis in order to help an individual decide whether or not to use KosherSwitch®-based products.  Most rabbis that have refused to endorse the KosherSwitch® have done so on non-Halachic grounds.

Even if permissible, won’t it confuse my kids when all along we’ve been teaching them that electricity is off limits? Won’t they use a regular light switch on Shabbat?

No.  Kids are smart, and they know the difference between something that’s permissible and something that’s not.  This is true even when the two items look identical, which is certainly not the case with the KosherSwitch® since it looks and behaves very differently than traditional switches.  One child provided the best affirmation when asked, “why are you allowed to use a KosherLamp™ on Shabbat?” they answered simply, “because it’s different!”  During our testing, children ranging from 3 to 5 years old were able to discern the difference between a KosherSwitch® and a regular switch, and to verbalize when it’s permissible to use a KosherSwitch® (“only when the light is green”).  More details are available here.

As I used the switch, the Status Light changed from green to red!

In our usage section,  we explain that one should use the KosherSwitch® on Shabbat and Yom Tov only when the Status Light is green, but not when it’s red.  In reality, the device continues to be dormant for the entire duration of the Status Light’s green and red cycle.  Only at the very end of the red cycle does the device become active.  So flicking the on/off button as the Status Light is changing from green to red is of no consequence.


Available Now!

KosherSwitch® Classic Wall Switch
KosherSwitch® Classic Wall Switch

Videos of Interest

Featured Shiur/Lecture

Rabbis & Poskim

HaGaon Rabbi Chaim Tzvi Shapiro
HaGaon Rabbi Chaim Tzvi Shapiro
HaGaon R Pinchas Zabihi Analyzing the KosherSwitch
HaGaon R Pinchas Zabihi Analyzing the KosherSwitch
HaGaon Rabbi Yitzhak Israeli Analyzing the KosherSwitch
HaGaon Rabbi Yitzhak Israeli Analyzing the KosherSwitch
HaGaon Rabbi Dzimitrovski Analyzing the KosherSwitch prototype
HaGaon Rabbi Dzimitrovski Analyzing the KosherSwitch prototype

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