Siman 213

Even though regarding one who sells the produce of a field or a tree it has been explained that he has not acquired them because they have not yet come into the world, unless he sold the field for its produce, and we do not say when he transferred the produce to him that he presumably transferred the field to him for the produce; nevertheless, one who sells the produce of a dovecote to his fellow—the pigeons that will be born—and similarly one who sells the produce of a beehive to his fellow—the honey that will be in the beehive—this person, even though he did not say "the dovecote for its produce" or "the beehive for its produce," nevertheless has acquired them even though the pigeons and the honey have not yet come into the world. This is because we say that presumably such was his intention, and he transferred to him the dovecote and the beehive for their produce. And the reason is that it is not similar to a field or a tree, which are significant in their own right even without the produce and are not nullified relative to their produce; and since he did not mention them explicitly, he does not transfer them to him by implication. But the dovecote and the beehive have no significance in their own right and are subordinate to the produce; therefore, even though he only mentioned the produce, he presumably transferred to him also the dovecote and the beehive themselves. And the implication of "produce of a dovecote and a beehive" is like the explicit statement of "a field and a tree for their produce" [Beit Yosef]. And similarly, one who sells the fish of a water channel, even though he only transferred the fish, he has acquired them even though the fish have not yet come into the world; it is as if he said, "I hereby sell you the water for its fish," for the water is subordinate to the fish [Levush]. And all the more so when he says, "I am selling you a dovecote for pigeons" or "a beehive for its honey," that he has acquired them. And even though the pigeons do not emerge from the body of the dovecote nor the honey from the body of the beehive, and it is not similar to the produce of the land and trees, nevertheless he has acquired them, for this is similar to one who sells a water channel to his fellow, in that he benefits from everything he may hunt in it, even though the fish are not from the body of the water but rather grew in the water; and so too regarding the pigeons and the honey [Sma]. Furthermore, "dovecote" and "pigeons" are one name, and a dovecote is included in pigeons and pigeons are included in a dovecote; and one who sells a dovecote has sold pigeons, and one who sells pigeons has sold a dovecote, as written in siman 220, because in the language of people they are included in one term, which is not the case with a tree and produce. This is because there are no pigeons without a dovecote and no dovecote without pigeons, for every pigeon needs a dovecote, and it is superior in this regard to a tree and produce.

The eggs and the chicks that are currently in the dovecote, even though they are in his dovecote and it is like his courtyard, nevertheless he cannot transfer ownership of them because he himself does not acquire them as long as they have not flown, and this matter is a rabbinic enactment. For they forbade any person from acquiring eggs and chicks when they are in the dovecote and the mother is crouching over them; since from the Torah it is forbidden to acquire the mother while she is crouching over them and one is obligated to send her away, as this is the mitzvah of shiluach haken, and the Sages, of blessed memory, feared that if we permit him to acquire the eggs and the chicks, he will also take the mother. Therefore, they enacted that he should not acquire them either. And since he himself has not acquired them, how can he transfer ownership of them to others? Therefore, one who wishes to transfer ownership of these chicks and eggs to his fellow taps on the dovecote so that they fly and the mothers are raised above the young, and afterwards he may transfer ownership to another through the acquisition of agav karka or through one of the other methods of acquisition by which movable property is acquired. And he can only transfer ownership of them when it is known that the mother is not crouching over them, for presumably the mother is crouching over the young. But when the mother has gone, even though she returned to them, he is no longer obligated in sending away since the nest is in his domain and it has become "prepared," as is written in Yoreh Deah siman 292, and he can transfer ownership of them to another. However, in a nest in the field which is not his and is hefker, it is forbidden for him to acquire them as long as the mother is crouching, as is written there.