This website is dedicated L’ilui Nishmas R’ Shmuel Yitzchak ben R’ Moshe A”H ר’ שמואל יצחק בן ר’ משה ע”ה
For Halachik questions please contact Rabbi Reingold at

Grama 11 – Meleches Machsheves 9, Sensors and Grama (Klal 9) Hilchos Shabbos – S0327

D'var Halacha
D'var Halacha
Grama 11 - Meleches Machsheves 9, Sensors and Grama (Klal 9) Hilchos Shabbos - S0327


Sponsorships for the upcoming Klalim, which discuss the 39 melachos of Shabbos, are available. Please contact Rabbi Reingold for more information at or 301.996.5910


We have finished Klal 9. The purpose of this Klal was to learn about broad klalim which come up regarding melachos of Shabbos. We will discuss a few other concepts not discussed by the Chayei Adam. We have discussed the concept of intent impacting the status of melacha, and now we are discussing grama.


We are continuing to discuss the concept of grama. A large amount of halachic discussion surrounding grama involves chaishanim, or sensors. Sensors cause various electronic effects, including motion, temperature, light, and so on. Another similar question regards voice commands. 


Many of these questions are discussed from the angle of davar she’eino miskavein (which would make it muttar) with the caveat that the action might be a psik reisha (which would make revert the action to assur). Other poskim approach these questions from the concept of misaseik, the concept that a person is involved in one activity while the assur activity happens concurrently as a result. 


The poskim do not approach the question from the angle of grama. Arugably, if one is walking down the street and a sensor is tripped, it should be considered an indirect action and therefore considered grama. The reason we do not approach it as grama is because once something becomes a standard way for a melacha to be perfomed, we consider it a normal means of performing the action, as we learned from the Chazon Ish. If so, for the purposes of Shabbos, it is no longer considered grama but rather meleches machsheves and it is chayav. 


Another possible arugment as to why grama could create a petur is that one of the definitions we learned in defining whether something is a maaseh or grama is kavanah, intent for the melacha (see s322). If the person intended for the result, they are chayav even though they performed the action in a grama fashion. If it happens on its own without intention for the result, it will not be considered meleches machsheves. 

Based on this argument, the Even Haozer writes that any case of psik reisha will remain a grama. Even if it may be a normal method of performing the melacha, if the person had no intent for it, there is a lack of meleches machsheves. If so, the action will revert back to grama and would be patur accoridng to him. 

We learned that the Avnei Nezer brings a proof from a Gemara against the requirement of the Even Haozer. The Gemara discusses a case of a person opening a door and fanning the flames of a fire by doing so. The Gemara says that it is assur, even though one has no intent, because it is a psik reisha. Although one has no intent to fan the flames, it is still assur. If so, the Avnei Nezer concludes that the exception of intent might be limited, in that once psik reisha reaches a level of halachic intent, it is considered as though one had intent to perform the action. In other words, the level of intent generated by a psik reisha is enouigh to generate a level of meleches machsheves and make one chayav.


If so, returning to the question of the sensors, we cannot use the arugment of grama. However, we do use the arguement of davar she’eino miskavein (with the caveat of psik reisha) and misaseik. 


Be’ezras Hashem, we will begin the next Klal in the upcoming shiur.



When it comes to grama switches, cars, guns, or other multi-step machines which are set in motion by one’s action, they are not considered grama but rather meleches machsheves because the entire machine is considered one system and therefore the direct action of the person who sets it in motion. 


Even though some sensors or voice commands may be patur in the world of nezikin, the concept of meleches machsheves would make them chayav in the world of Shabbos. Rather, they are patur because they are either considered a davar she’eino miskavein or misaseik.


You Might Also Like

Sign Up to Receive Our Free Daily Email That Includes:

[email-posts-subscribers namefield="NOT" desc="" group="Public"]
Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors