Chullin 70: A Blemished Bechor as a Fetus

Some points from today's daf:

• the bechor, firstborn of a kosher animal, is given to the kohanim
• the kohen brings the bechor to be sacrificed in the Temple in Jerusalem
• the kohen can eat the meat from the sacrifice
• if the animal develops a mum, blemish, it is not redeemed and exchanged like other sanctified animals
• a mum can be eaten outside of the Temple by the kohen
• thus the laws of bechor continue to apply today
• because it will not work, instead bechorim are sold to non-Jews to discontinue the laws of bechor
• a bechor must be a petter rechem, opener of the womb
• if only parts of the fetus emerge, the animal has no sanctity and it can be killed to save the mother; its meat given to the dogs
• Rava asks about what constitutes a petter rechem:
• If a weasel put its head into the womb and pulled out the fetus, then put it back and spit it out, and then the fetus came out on its own...?
• if one joined the wombs of two animals and one fetus entered the womb of the other - does it exempt itself, its mother, and/or the other fetus from the laws of bechor...?
• these questions are teiku, they remain undecided.
• Tosafot say that these impossible cases are relevant for the sake of Torah study
• Steinsaltz notes that today's questions of surrogacy prove these questions relevant today