One who buys the fetus of a donkey belonging to a non-Jew, or sells [one] to him, even though it is not permissible, or he enters into a partnership with him, or he receives [a donkey] from him to hold, or gives [one] to him to hold, is exempt from the bechor laws, as it is stated (Numbers 3:13): in Israel —- but not in others.  [The donkeys of] Kohanim and Leviim are exempt because of a kal vachomer: If they exempted the Yisraelim in the Desert, it is only proper that they should exempt their own.

[If] a cow bore something resembling a donkey, or [if] a donkey bore something resembling a horse, it is exempt from bechor laws; as it is stated (Exodus 13:13, 34:20): The firstborn of a donkey, The firstborn of a donkey, twice —- until the bearer is a donkey and the offspring is a donkey.  What is their status in regard to eating? [If] a kosher animal bore something resembling an unkosher animal, it is permissible for eating; but [if] an unkosher animal bore something resembling a kosher animal, it is forbidden for eating; for whatever comes out of something unkosher is unkosher, and whatever comes out of something kosher is kosher. [If] an unkosher fish swallowed a kosher fish, the kosher fish is permissible for eating; but [if] a kosher one swallowed an unkosher fish, it is prohibited for eating, because this is not its growth.

[If] a donkey which had not yet given birth bore two males —- he must give one lamb to a Kohen; [if it bore] a male and a female —- he must set aside one [lamb] for himself. [If] two donkeys which had not yet given birth bore two males —- he must give two lambs to a Kohen; [if they bore] a male and a female, or two males and a female —- he must give one lamb to a Kohen; [if] two females and a male, or two males and two females —- there is nothing here for a Kohen.

[If] a [donkey] which had previously given birth and one which had not yet given birth [now] bore two males —- he must give one lamb to a Kohen; [if they bore] a male and a female —- he must set aside one lamb for himself.  As it states (Exodus 34:20): The firstborn of a donkey you shall redeem with a seh —- [it may be] of sheep or goats, a male or a female, old or young, perfect or blemished. He may redeem with it many times; it enters the pen to be tithed; and if it dies, one may derive benefit from it.

One may not redeem [a firstborn donkey] with a calf, an undomesticated beast, a slaughtered animal, a tereifah, a hybrid, or a koy. R’ Elazar permits [redemption] with a hybrid because it is a seh; but he prohibits [redemption] with a koy, because it is doubtful. [If he] gave it to a Kohen, the Kohen may not keep it until he sets aside a lamb or kid in its stead.

[If] one sets aside a [lamb for] redemption of a firstborn donkey, and it dies —- R’ Eliezer says: One is responsible for it, as with the five selaim of the son. The Sages, however, say: One is not responsible for it, as with the redemption of maaser sheni. R’ Yehoshua and R’ Tzadok testified concerning the redemption of a firstborn donkey that died, that there is nothing here for a Kohen.  If the firstborn donkey dies —- R’ Eliezer says: It must be buried, and benefit may be derived from the lamb. The Sages, however, say: It need not be buried, and the lamb belongs to a Kohen.

[If] he does not wish to redeem it, he must decapitate it with a large knife from behind and bury it.  The precept of redemption takes precedence over the precept of decapitation, as it states (Ex. 13:13): And if you do not redeem it, you shall decapitate it. The precept of yiud takes precedence over the precept of redemption, as it states (Ex. 21:8): Who did not designate her, he shall cause her to be redeemed.  The precept of yibum takes precedence over the precept of chalitzah —- in the early days, when they would intend [to perform yibum] for the sake of [fulfilling] the precept; but now that they do not intend [to perform yibum] for the sake of [fulfilling] the precept, they said: The precept of chalitzah takes precedence over the precept of yibum.  The precept of redemption is on the owner. He takes precedence over any other person, as it is said (Lev. 27:27): “And if it is not redeemed, it shall be sold for its valuation.”

One who buys the fetus of a cow belonging to a non-Jew, or sells [one] to him, even though it is not permissible, [or] enters into a partnership with him, or receives [a cow] from him to hold, or gives [one] to him to hold —- is exempt from bechor laws; as it states (Numbers 3:13): in Israel —- but not in others.  Kohanim and Levites are liable. They were not exempted from the bechor [law] of kosher animals; they were exempted only from the redemption of the son and from [the law of] the firstborn donkey.

[If] she was flying — as long as her wings touch the nest, he is obligated to send [her] away; [if] her wings do not touch the nest, he is exempt from sending [her] away. [If] there is only one chick or one egg, he is obligated to send away [the mother bird], as it is stated: A nest — a nest in any case. [If] there were fledglings or infertile eggs, he is exempt from sending away [the mother bird], as it is stated: And the mother bird is sitting on the chicks or on the eggs — just as the chicks are viable, so must the eggs be viable, which excludes infertile ones; and just as the eggs need their mother, so do the chickes need their mother, which excludes fledglings. [If] he sent her away and she returned, he sent her away and she returned, even four of five times, he is [still] obligated [to send her away], as it is stated: You shall surely send away. [If] one says, ‘‘I will take the mother bird and send away the young,’’ he is obligated to send away [the mother bird], as it is stated: You shall surely send away the mother bird. [If] he took the young and returned them to the nest, and afterwards the mother bird returned upon them, he is exempt from sending [her] away.

[If] one takes a mother bird while on her young — R’ Yehudah says: He incurs the penalty of lashes, and he need not send [her] away. But the Sages say: He must send [her] away, and he does not incur the penalty of lashes. This is the rule: Any negative commandment that has in it a positive commandment, one does not incur the penalty of lashes for its violation.

A person may not take the mother bird while on the young even to purify a metzora. Now, if concerning an easy commandment that involves a loss of about an issar, the Torah states: In order that it be good for you and you may live long, how much more does this apply to the difficult commandments in the Torah!