In Memory of Rav Yisrael Rozen zt”l: A Ringing Endorsement of the Zomet Grama Gadgetry by Rabbi Chaim Jachter


A Torah Academy of Bergen County alumnus recently approached me with a dilemma. The alumnus serves as the distinguished rabbi of a respected community which has some handicapped members who wish to use the Zomet Institute electric wheelchairs and chair lifts specially designed for Shabbat use. On the one hand, there is great need, but on the other hand Rav Yosef Dov Soloveitchik did not subscribe to the theory on which the Zomet Institute’s Shabbat mechanisms are based. In honor of the recently deceased founder of the Zomet Institute, Rav Yisrael Rozen zt”l, I will explain why I encouraged the TABC alumnus to embrace the Zomet Institute wheelchair and chair lift when necessary. 


Since the Shabbat wheelchair and chairlift operate by means of Grama, indirect action, it is necessary to review the application of Grama in the modern environment.

 The Torah (Shemot 20:10) states, "Lo Ta'aseh Melachah," “Do not perform Melachah,” on Shabbat. The Gemara (Shabbat 120b) infers that “performing” a Melachah (loosely translated as work) is forbidden, while indirectly causing Melachah is not forbidden.  Despite this seemingly all-encompassing permission, we shall see that leniencies based on Grama have been employed only in limited situations.

Grama and Intent

The issue of Grama emerges, for example, in the context of refrigerators. Rav Shlomo Zalman Auerbach permits the opening of a refrigerator door even when the motor is not running, despite the fact that opening the door inevitably will trigger motor activity. Rav Auerbach ruled that the impact of opening the door on the motor is indirect, and Grama is not prohibited when one does not intend to cause the result. Since one who opens the door intends to take food and not to trigger the motor, indirectly causing the motor to go on is not prohibited on Shabbat or Yom Tov.

There are cases, however, where Grama is permitted even when one's intention is to cause the resulting act. For instance, the Shulchan Aruch (Orach Chaim 334:22) permits one to place barrels of water in the path of a fire burning on Shabbat so that the heat will burst the barrels, causing the water to surge forth and extinguish the fire. The Rama (ad. loc., based on the Mordechai Shabbat 399) cautions, however, that the permission to intentionally perform an act of Grama is limited to cases where one seeks to avoid great loss, such as putting out a fire. The Bei’ur Halachah (ad. loc. s.v. DeGram Kibui) clarifies that this rule applies to all of the thirty-nine Melachot (forbidden activities) of Shabbat and not only to Mechabeh (fire-extinguishing).

The Rama understands that Chazal created a Rabbinic prohibition to indirectly cause Melachah on Shabbat in situations other than a case of great need. Danger to life is not required to permit Grama; rather, great need is sufficient cause. In other words, Grama is permitted for essential needs even if they are not life-threatening needs. This restriction seems to stem from concern that if Grama was permitted in all situations on Shabbat, Shabbat observance would be eviscerated, as all work could be accomplished on Shabbat indirectly. The Ramban (commentary to VaYikra 23:24) notes that due to this concern, Chazal forbade a host of activities, such as engaging in business deals and asking a non-Jew to perform Melachah on one's behalf. Chazal wished to avoid sanctioning one who, on the one hand does not technically violate Shabbat, but on the other hand has not observed a meaningful Shabbat.

Contemporary Applications of Grama

The Gemara (Sanhedrin 77a) presents a situation referred to as "Sof Chamah Lavo," a case where one ties up another individual in the desert during the night and the sun rises the subsequent day and the victim dies due to the heat. The Gemara classifies this as an act of Retzichah by Grama (indirect killing).  Rashi (ad. loc. s.v. Kofto and s.v. O SheParah) explains that because the killing agent was not present at the time of the perpetrator's action, the murder is classified as indirect.

The Chazon Ish (O.C. 38:4) applies the Sof Chamah Lavo principle to solve the problems involved in milking cows on Shabbat. He permits attaching the milking-machine pipes to the cow's udder before the flow of electricity begins. The machine can subsequently be turned on by a timer, and the one who attached the pipes to the udder is not considered to have milked directly. Since the electricity is not flowing when the pipes are attached, it is analogous to the sun not being present when the individual tied up another person in the desert. The Chazon Ish incorporates the Rama as well, reasoning that the indirect milking should be permitted due to the great need to milk cows on Shabbat resulting from both the suffering of the cows and the severe financial strain on dairy farmers.

Another application of the Grama principle is the permission granted by the Shemirat Shabbat KeHilchatah (13:25, written by Rav Shlomo Zalman Auerbach and Rav Yehoshua Neuwirth) to adjust certain timers to turn on a light earlier than scheduled in case of great need. Once again, since the electricity is not flowing when the timer is adjusted, it is comparable to the sun not being present at the time when the victim is tied up.

The Zomet Institute produces many items that operate using the Sof Chamah Lavo principle in highly essential, non-life-threatening situations. These gadgets include wheelchairs, hospital equipment, and vehicles for patrolling areas in Israel that are essential to monitor but not exceptionally dangerous. 

A popular Zomet product is their "Grama phone," which operates in a similar manner to their other products. When one raises the receiver, no electric circuit is completed (unlike in a conventional phone). Instead, an electric pulse is sent out by the phone every ten seconds or so to detect if the receiver has been lifted. When it detects that the receiver has been lifted, the circuit is completed. Again, the absence of the pulse when one lifts the telephone parallels the sun that is not at hand when the tying is completed. Rav Ovadia Yosef wholeheartedly endorses the use of the Grama phone for essential needs in a brief responsum printed in Techumin (1:518). He writes that “it is permitted according to all opinions.”  Rav Ovadia’s son Rav Yitzchak Yosef continues in the path of his father and endorses Zomet Institute’s Shabbat security gate mechanism which operates using the Grama principle (Techumin 34:15-18). Rav Shlomo Zalman Auerbach and Rav Yehoshua Neuwirth endorsed it as well (cited in Rav Rozen’s essay on Grama that appears in Techumin volume 34). 

The Grama phone is used in many venues in Israel, especially in the Israel Defense Forces, which has purchased hundreds of these phones for use in essential, non-critical situations on Shabbat. Grama phones have greatly enhanced Shabbat observance in the IDF, as a Grama phone is used instead of a regular phone except in case of a full-fledged emergency.

Objections to Zomet’s Grama Mechanisms

However, Rav Yosef Dov Soloveitchik (cited by Rav Hershel Schachter in his BeIkvei HaTzon pp. 44-45) does not subscribe to the Chazon Ish's application of the Sof Chamah Lavo principle. Rav Soloveitchik argues that since the electricity is operational when one performs his actions, it is not analogous to the classic cases of indirectly extinguishing a fire or Sof Chamah Lavo, where the "active item" is not present when one acts. One may respond that in the classic cases, the natural forces move the fire and the sun are extant when the action is performed, just as the electricity moving the timer is present at the time when one acts. Accordingly, it would be inaccurate to say that the timer itself parallels the classic fire and sun; rather, the electricity driving the timer parallels the natural forces that drive the sun and fire.[23]

TABC alumnus Rav Avi Levinson (’08) notes that Zomet Grama mechanisms seem to run counter to the Rosh (Bava Kama 6:11), who writes that systems that work normally using Grama cannot take advantage of the leniency of Grama. Even according to Rav Shlomo Zalman Auerbach who believes that the Rosh applies only when one intends to create the resultant action, it would appear that all of the contemporary systems that are set up to be routinely run via Grama are not to be regarded as Grama. 

One could respond that the Rosh applies to systems used routinely in ordinary circumstances. For example, the Even HaOzeir (O.C. 328) applies the Rosh’s concept to a water-powered mill, and Rav Chaim Ozer Grodzinsky (Teshuvot Achiezer 3:60) applies the Rosh’s concept to a conventional electric light.  However, the Chazon Ish and those following in his footsteps deal with activities such as milking cows and using an electric wheelchair that are not usually performed via Grama.

Thus, since Zomet Grama gadgetry has a strong basis in the rulings of the Chazon Ish, Rav Shlomo Zalman Auerbach, Rav Ovadia Yosef, Rav Yitzchak Yosef, and Rav Yehoshua Neuwirth, I strongly encouraged the TABC alumnus to permit the use of Zomet Grama products to enhance the Shabbat of the handicapped. Nonwithstanding the profound love and respect I have for my rebbe Rav Soloveitchik, it seems that his reasoning regarding Grama and electricity is not conclusive. Moreover, Zomet gadgetry has been accepted in many sectors of the Israeli Orthodox community. Rav Ovadia Yosef’s resounding endorsement of the Grama phone, stating “it is permitted according to all opinions,” carries great weight and makes for a compelling reason for the adoption of Zomet Grama mechanisms when necessary. 

Rav Yisrael Rozen zt”l, the founding head of the Zomet Institute, who just recently left this world, has made an enormous contribution to the Jewish People, enabling the observance of Shabbat in a technologically advanced Jewish State. May his memory serve as a blessing and may his legacy continue to flourish by those who follow in his path. 

[23] I discuss this issue at greater length in my essay printed in Yeshiva University's Beit Yitzchak (35:382-383).

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