Last time, I focused on the Gemara (Brachos 47) about Rebi Eliezer freeing his slave, to bring the Rosh about Parshas Zachor. This time we'll go through several Tosfos and a famous Beis Yosef about sinning to benefit someone else (i.e., to prevent him from sinning), "chatei kidei sheyizkeh chaveircha." But first I want to add a little to the previous post.
1. We see (or will see by the end of this post) that someone who transgresses an asei is considered a chotei. We say al cheit on Yom Kippur even for mitzvos asei.
2. How is freeing the slave mitzvah habaah baaveirah - the mitzvah is not fulfilled when the master frees the slave, the mitzvah is only fulfilled when they say kedusha or borchu or read parshas zachor? It could be that even before you say borchu etc. there already is a mitzvah involved when the minyan gathers. See Avos 3:6 the shechina dwells on a minyan in a special way. Even if that's not a proof, it's more explicit in Brachos 6b - when Hashem comes to Beis Medrash and does not find a minyan, He immediately gets mad. Why? My Rebbie Rav Moshe Soloveichik Shlit"a said unlike aliya laregel which is us going to Hashem's house, the Beis Hamikdash, a shul is our home for G-d. If a minyan is not present at the time of prayer, it is analogous to inviting a guest to your home but the host is late. Bad manners to say the least. So we see the assembly of a minyan already has a special status. Perhaps that is why Tosfos in Brachos considers freeing the slave as a mitzvah habaah baaveirah.
3. When Gittin 38b mentions the story of Rebi Eliezer freeing his slave, it just says "for a mitzvah, it is different," and does not say a public mitzvah like the gemara in Brachos does. In fact, Tosfos (Gittin 38a s.v. kol) says even the mitzvah of fulfilling the wishes of a dying man is enough to override "leolam bahem taavodu" and that is not a mitzvah dioraissa. So that Tosfos holds when there is a need, even "lekayim divrei hames" is enough to let us free the slave.
Shabbos 4a discusses if one put bread in an oven close to Shabbos, may he remove them from the oven (which is not mutar - Ran on Rif says it's asur midirabanan, Rif says it's just a chochma) before it reaches a level of being considered baked, because if it becomes baked you're chayav misa. It is not permitted for someone else to remove the bread from the oven, because one may not sin for someone else to benefit (in this case he won't be chayav misa).
Tosfos (s.v. vechi) asks from several cases, but I'll focus on the freeing of a slave because that's our topic. How can you free your slave, even if it's for a mitzvah (of minyan or parshas zachor) if you will transgress the asei of "leolam bahem taavodu?" Also, there is a gemara (Gittin 41b) if a slave was owned by partners and one of them freed the slave, the slave is in a state of limbo - he can't marry a Jewish woman because he's partially a slave, and he can't marry a shifcha because he's partially free. Therefore we force the second partner to free the slave. Tosfos asks how can we do this - the master sins to benefit someone else? Tosfos gives two answers: 1) For a great mitzvah, we do say sin to prevent someone else from sinning. Here, the slave will not be able to procreate, which is a great mitzvah, so it's better for the master to free him than for him not to fulfill procreation. This is the same logic as the gemara in Brachos - for a public mitzvah we do free the slave; something that important does override the asei of leolam bahem taavodu. 2) We only don't let someone to sin to save (protect) someone else when the latter acted in a neglectful manner, like putting the bread in the oven too close to Shabbos. But this eved was not in a bad situation becoause of his own negligence, so we don't prohibit the master from setting him free.
To be continued....