Photo Credit: Jewish Press

A Matter Of Doubt
‘When You Make [Four] Applications…’
(Zevachim 80a)



We learned in Perek Eizehu Mekoman that a korban bechor (56b) requires a single blood application on the mizbeach. If one adds to this number, one violates “bal tosif – do not add” (Devarim 4:2, 13:1). We also learned that both the korban olah (53b) and korban shelamim (55a) require four applications. If one applies fewer than the required number, one violates “bal tigra – do not diminish” (Devarim 4:2, 13:1).

The mishnah on our daf discusses a dispute between R. Eliezer and R. Yehoshua regarding blood of a bechor that was inadvertently mixed with the blood of either an olah or a shelamim. R. Eliezer maintains that four applications are made; R. Yehoshua maintains one application is made. The former is more concerned about bal tigra and the latter is more concerned about bal tosif. The halacha (Rambam, Hilchos Pesulei Hamizbeach 2:11) follows R. Yehoshua.

Tefillin on Chol HaMoed

The Mechaber and Rema (Orach Chayim 31:2) disagree about donning tefillin on Chol HaMoed. The Mechaber rules that doing so is forbidden. The Rema rules that doing so is mandatory. According to the Mechaber, if a person goes ahead and dons tefillin on Chol HaMoed, he is in violation of bal tosif.

The Magen Avraham (ad. loc. sk2), however, posits that a person who dons tefillin on Chol HaMoed due to halachic doubt (he wants to conduct himself stringently in accordance with the ruling of Rema) need not be concerned with violating bal tosif because one does not violate this prohibition when performing a mitzvah due to halachic doubt. One only violates bal tosif when one wishes to add a mitzvah to the Torah.

Fulfilling An Obligation

Yalkut Me’iri, citing Responsa Shoel Umeishiv, asks: According to the Magen Avraham, it is difficult to understand R. Yehoshua’s reason for forbidding one from making additional blood applications from the mixture due to bal tosif considering that the person’s intent is not to add to the mitzvos but to fulfill the obligations of the korban olah (or shelamim).

Rabbi Zev Dickstein, editor of Al Hadaf, suggests that although he wishes to fulfill all obligations of the olah (or shelamim), at the same time, it is clear to him that he is adding to the blood applications of the bechor.

The Me’iri (Rosh Hashanah to 28b) explains that the parameters of bal tosif actually lay at the heart of the dispute between R. Eliezer and R. Yehoshua. R. Eliezer maintains that there is no bal tosif since he is only adding blood applications due to safek while R. Yehoshua argues that bal tosif even applies if one is adding due to halachic doubt.


Previous articleParshas Balak
Next articleTwo Bites At The Apple (Shulchan Aruch, Choshen Mishpat 79:10)
Rabbi Yaakov Klass is chairman of the Presidium of the Rabbinical Alliance of America; rav of Congregation K’hal Bnei Matisyahu in Flatbush, Brooklyn; and Torah Editor of The Jewish Press. He can be contacted at and