Bechoros 5:2-3

Bechoros 5:2

Beis Shammai say that a Yisroel (an Israelite) may not be invited by a kohein to eat a blemished firstborn, though Beis Hillel permit even a non-Jew to join the kohein. If a firstborn animal suffered from an excessive accumulation of bodily fluids, one may not let its blood even if failure to do so will result in the animal’s death; this is the opinion of Rabbi Yehuda. The Sages, however, say that one may let the animal’s blood so long as he doesn’t blemish it. If one did cause a blemish, the animal may not be slaughtered because of it (because he caused it himself). Rabbi Shimon says that one may let the animal’s blood even if he blemishes it (because causing the blemish is an unintended side effect).

Bechoros 5:3

Rabbi Eliezer says that if one cuts a slit in the ear of a firstborn animal, it may never be slaughtered (even if it later acquires another blemish). The Sages say that if the animal later develops another blemish, it may then be slaughtered because of that second blemish. It once happened that a Roman official saw an old male sheep with very long wool. He asked why this was and was told that it was a firstborn animal and that it could not be slaughtered until it developed a blemish. The Roman official took a knife and slit the animal’s ear. The matter was brought to the Sages, who permitted the animal. When the Roman saw that they permitted it, he started slitting the ears of other animals, which the Sages then prohibited. It once happened that some children were playing in a field and they tied the tails of some sheep together, causing the tail of a firstborn animal to break. The matter was brought to the Sages, who permitted the animal. When people saw that the Sages permitted it, they tied the tails of other firstborn animals together and the Sages prohibited those animals. The general principle is that if an animal is blemished with its owner’s approval, it is prohibited; if it is blemished without his approval, it is permitted.