The Mishnah (8:10) records the debate regarding cups of blood from two korbanot that got mixed up. The blood from both these korbanot are meant to be thrown on the bottom half of the mizbeach, however one requires it on one location, while the other required to be thrown on two corners. The Mishnah refers to this as "four" placements, because the blood thrown in this fashion reaches the four sides of the mizbeach.
R' Eliezer argues that the blood should be thrown twice for both bloods*,* while R' Yehoshua maintains that the blood can only be thrown once for each. The Bartenura explains that even though, according to R' Eliezer's solution, some of the blood will be thrown unnecessarily, he simply views that blood as being like water. R' Yehoshua however wishes to avoid violating the prohibition of adding to mitzvah -- bal tosif. Furthermore, as long as the blood reaches the bottom half of the mizbeach at least once, the korban is valid. That is true even for a korban that ideally requires the additional placements of blood.
The Mishnah however records the debate between the two as follows. R' Eliezer argues that R' Yehoshua's solution is a violation of bal tigra -- deducting from mitzvot -- while R' Yehoshua counters that R' Eliezer's solution violates bal tosif. In the end, both argue that the prohibition is not violated in this case where there is a mixture.1 Yet R' Yehoshua adds that being passive and not actively coming up against bal tosif is preferable.
The Tosfot Yom Tov explains that, as noted above, according to R' Eliezer there is no issue of bal tosif. The discussion in the Mishnah is only working with R' Yehoshua's position that bal tosif is a consideration.
Recall that the Bartenura explained that R' Yehoshua further argues that an additional justification for performing only one placement is because it is sufficient, bedi'eved, for both korbanot. The Keren Orah (Eiruvin 100a) discusses why this rationale is important. He first cites the Maharsha who explains that if it both placements were necessary, R' Yehoshua would agree that "four" placements must be performed. The Keren Orah however argues that if the four were critical, then it would seem that R' Yehoshua would argue that there is no solution and neither cup could be used. The Keren Orah argues that the Maharasha's solution in the R' Yehoshua's eyes would still be bal tosif. 2
The Ohr Sameach (Pesulei Mukdashim 2:11) cites the Turi Even. He first confirms that if one refrained from engaging in a mitzvah, he would not violate bal tigra. That being the case, no blood should be able to be thrown on the mizbeach to avoid bal tosif and bal tigra. By doing one placement, one is actively causing the prohibition of bal tigra to be violated.
The Ohr Sameach however dismisses the question. He explains that in that case, bal tigra would not be actively violated when doing the first placement. When the korban was slaughter, he was obligated to perform (at least) that first placement. Bal tigra is only an issue when refraining from performing the addition placement, which is occurring passively.4
1 The Ritva (Rosh Hashana 28b) explains that bal tosif is only an issue when facing the mitzvah alone and adding to the performance of that mitzvah. In this case, the additional placement that are being performed to the wrong blood, is not for the fulfilment of that korban, but rather to ensure sufficient blood was placed on the mizbeach for the blood that required it.
2 Perhaps the Maharasha's position is based on the simple understanding of the Mishnah that bal tosif is not an issue when we have a mixture -- see the previous footnote. The Keren Orah in the end suggests that at least one placement should be able to be performed unless the single placement would be considered incomplete and invalid for a korban that required more.
3 The Ohr Sameach compares this with the case of one who is to perform a brit millah on Shabbat and the various semamanim necessary for after the brit spill, which would require chilul Shabbat to prepare replacements. We do not say that they should delay the brit. The mitzvah at hand is to perform the brit on Shabbat. After that, due to pikuach nefesh one can the prepare the semamanim.
Receive our publication with an in depth article and revision questions.