Issur Melakha and the Shabbat Day of Rest Part 3

  • Rav Doniel Schreiber



By Rav Doniel Schreiber


Shiur #18: Issur Melakha and the Shabbat Day of Rest

Part III



The previous shiur discussed the laws of davar she-eino mitkaven, i.e. where intended, permitted act "A" yields unintended prohibited act "B".  According to the halakha, one is not liable in such a case where prohibited act "B" might or might not have occurred as a result of permitted act "A".  However, what is the law in a case of a davar she-eino mitkaven pesik reisha, i.e. where unintended, prohibited act "B" will DEFINITELY occur as a result of permitted act "A", such as turning on the light in a refrigerator by opening the refrigerator door?


The term "pesik reisha" is a rabbinic catch-phrase for something that will definitely occur, and derives from the phrase of the gemara: "pesik reisha ve-lo yamut," "cut off its (the chicken's) head and let it not die."  The case revolves around one who wants to decapitate and use the head of a chicken for some purpose, and does not intend to kill the chicken thereby.  According to the gemara (Shabbat 75a), all agree in such a case that one is liable since permitted act "A" (cutting off the head of a chicken) will inevitably lead to unintended prohibited act "B" (the killing of the chicken, which is forbidden under the av melakha of slaughtering, shochet). 


While some authorities rule that there has been only a rabbinic violation in this case (Taz OC 340:2 and Ma'amar Mordechai 316:10), most rishonim and poskim rule that a Torah violation has occurred.  Nonetheless, these rishonim and poskim rule that a Torah violation has occurred in this case only when unintended prohibited act "B" is "nicha lei," i.e. of BENEFIT to the one who performed the action.  In a case where one has no benefit from act "B", "davar she-eino mitkaven pesik reisha De-LO nicha lei," they understand that a rabbinic violation has occurred.  See Rambam, Shabbat 1:6, Tosefot and Rosh (Shabbat 103a), and Ramban and Ran (end of Shabbat, chap.  14), Ritva (Sukka 33b), Tur (OC 320), Beit Yosef (OC 320), Shulchan Arukh (OC 320:18) and MB 320:52,55, and Sha'ar Ha-tziyun 320:53.


A minority of rishonim and poskim rule that where one has no benefit from act "B", no violation has occurred at all (Arukh, cited in Tosefot Shabbat 103a, Ravyah vol. 1, Mesechet Shabbat, no. 194, Rabbeinu Yerucham, netiv 12:14, and apparently R. Eliezer Me-metz, in Sefer Yereim, no. 102, as well as Rambam according to Reb Chaim Brisker in Chidushei Ha-grach al Ha-Rambam Shabbat 10:17, Mishpatei Uziel, OC 19, Reb Chaim Brisker, cited by Rabbi S.Z. Reiger in Hapardes, v. 3, 1934).  See also Ha-amek Sheilah, Sheilta 105, note 5.


Although we are not lenient on the basis of this minority opinion alone, we do utilize it in conjunction with other grounds for leniency.  For instance, one drank a cup of hot tea on Shabbat, and some droplets remaining at the bottom cooled down.  May one refill this cup with hot water from the urn, or does one violate the prohibition to cook on Shabbat by heating up the cold droplets of tea?


R. Moshe Feinstein zt"l (Igrot Moshe OC, vol. 1, no. 93, and OC vol. 4, no. 74, laws of bishul note 19) writes that it is permitted.  His reasoning is that while in practice we treat previously cooked liquids, which have cooled, as raw food subject to the prohibition of cooking, nonetheless, inasmuch as in principle (but not in practice) most authorities are lenient in this regard, and this is a case of davar she-eino mitkaven pesik reisha de-lo nicha lei, as one does not intend to heat up the droplets and gains no real benefit from it, since they are only droplets, one may be lenient.  Similarly, see MB 321:57.


What is the rationale of the position that one is liable for performing melakha on Shabbat in a case of davar she-eino mitkaven pesik reisha de-nicha lei? Rishonim differ; some are of the opinion that in this case one is considered to have intended to cause the prohibited act (Rashi, Sukka 33b, and Tosefot, Shabbat 42b), while others understand that although the melakha is unintended, the individual is aware that his actions will result in a melakha, and this awareness itself imposes liability (Rabbeinu Chananel, Shabbat 133a).


For further research: Rishonim and Achronim disagree as to whether pesik reisha is liable whenever the forbidden by-product is inevitable (Rabbeinu Chananel, Shabbat 111b, Mordechai, Shabbat, no.  329, and MB in Sha'ar Ha-tziyun 316:32), or only where there is no other way to accomplish the desired goal without also violating a melakha, but if there is another way, then even choosing the method which inevitably violates the melakha is considered  mutar (Rashi, Zevachim 91b, Rashba Shabbat 107a).  See also Shiltei Gibborim, Shabbat 38a in Rif, note 3.


What remains unclear from the gemara is the law regarding an instance where performing permitted action "A" inevitably causes RABBINICALLY prohibited unintended act "B" that is nicha lei, of benefit.  For instance, if one intends to move a heavy bench indoors and in doing so drags it through the yard making a furrow (constituting a rabbinic violation as the furrow was created in an unusual manner) or if one intends to open a refrigerator door and in doing so turns on a fluorescent light inside (which is also a rabbinic violation – to be discussed in a later shiur), has there been a violation?


Some authorities are lenient and consider no violation to have occurred even though it is nicha lei (Trumat Ha'deshen, no.  64 and 67, Rambam, Shabbat 25:5, Rabbeinu Tam in Sefer Ha-yashar, no.  233, and Meiri, Shabbat 29b and R. Akiva Eiger, cited in Chatam Sofer YD 140 [see, however, MB 314:11], and others cited in Yabia Omer 4:34 OC and Yalkut Yosef, Shabbat vol. 5, p. 233, note 13), while most others are stringent (Rashba, Shabbat 120b, Ritva, Ketubot 6b, Magen Avraham 314:5, Eliyahu Rabba 314:22, Gra 314:1, Shulchan Arukh Ha-rav 337:1, and MB 314:11).


What emerges, then, is that the vast majority of later poskim rule that one is liable whether the pesik reisha de-nicha lei occurred in the context of a Torah or rabbinic prohibition, the former being a Torah violation and the latter a rabbinic one.


For further research: While we are generally stringent when there is a pesik reisha de-nicha lei, there are instances where poskim do use pesik reisha as a factor in establishing a leniency, even when nicha lei, as in certain cases of amira le-nochri (asking a non-Jew to perform melakha) such as asking a non-Jew to open a refrigerator causing the light inside to turn on.  Or safeik safeika (double doubt).  See MB 253:99, MB 314:11, Yabia Omer 4:34 OC, ibid.  5:28, note 1, OC, and Yalkut Yosef, Shabbat vol.  5, p. 233, note 13.


The next shiur will discuss the law regarding of a common case: davar she-eino mitkaven pesik reisha De-LO nicha lei in the context of a RABBINIC prohibition, e.g. motion detectors.