Siman 210

Just as a person cannot transfer ownership of a thing that has not yet come into the world, so too he cannot transfer ownership to one who has not yet come into the world, for the kinyan has no one upon whom to take effect. Therefore, one who grants merit to the son of Reuven who is to be born—even if Reuven's wife was pregnant and the fetus was also recognizable [Tur]—and said, "I transfer ownership of this object to the fetus of Reuven," the fetus does not acquire it. And even if he said that he should acquire it when he is born, and he did not retract and did not die until he was born, and even if the kinyan remains extant—such as where one person granted merit in the object on behalf of the fetus and pulled it into his domain and granted merit in the domain to the fetus, and when he was born the object was still in the domain of the one who acquired it—nevertheless, he does not acquire it. This is unlike those who disagree and say that certainly if the transferor retracted before the fetus was born, or if he died before its birth, or even if he did not retract and did not die but the kinyan was via kinyan sudar or chazakah where the acquirer acquired on behalf of the fetus and by the time he was born the kinyan had already ceased, it is obvious that the fetus did not acquire even if he said "when he is born"; but when another acquired on his behalf via meshikah and the object is still in the domain of the acquirer when he was born, and the acquirer granted him merit in the domain, and the transferor did not retract, this newborn acquires if he said "when he is born," because the kinyan takes effect now after his birth—for we do not rule accordingly. And even according to the opinion in siman 209, section 9, that regarding a thing that has not yet come into the world one acquires in such a case, this is because the buyer is in the world, and since the transferor said to him "acquire when the thing comes into the world" and the kinyan was then in its completeness, he acquires after the thing came into the world; but this is not so here, for all the words that the transferor spoke are in vain since the buyer was not in the world at all. Nevertheless, there are those who say that if the fetus seized it after he was born before the retraction of the transferor, we do not remove it from his hand, just as in the case of a thing that has not yet come into the world [Netivot HaMishpat].

Our Sages, of blessed memory, said that even though one who transfers ownership to a fetus does not effect a transfer, nevertheless, if the fetus was his son and he transferred a gift to him through another, the fetus acquires it even if he did not say "when he is born," because a person's mind is close to his son and he wholeheartedly intends to transfer ownership to him [Bava Batra 142a]. And specifically when his wife is pregnant at the time of the gift, and even if her pregnancy was not yet recognizable, for in any case there is closeness of mind; but when she is not pregnant and he transferred to the fetus she will conceive, it is nothing. And there is one who requires that forty days of her pregnancy must have passed [Shach], in which the formation of the offspring is completed. And likewise, specifically when he is born a viable child, but if he was not a viable child, his mind is not close to him [Sma]. And the acquisition of the son is when he is born; therefore, if the father retracted before he was born, or the father died before he was born, he does not acquire by virtue of his gift [Netivot HaMishpat]. And some say that this which the Sages said, that one who transfers ownership to his own fetus acquires, is only in the case of a shekhiv mera and not a healthy person, because a fetus is not a legal entity for acquisition at all; only in the case of a shekhiv mera did they institute this, since a person's mind is close to his offspring, if his words are not upheld, his mind will be distressed. And the first opinion holds that this is by law, for a fetus is a legal entity for acquisition, and only regarding a fetus that is not his own, his mind did not resolve to transfer ownership to him with a whole heart even when he is born; but to his son and daughter, he transfers with a complete acquisition and he acquires when he is born. And according to all opinions, specifically his son and daughter, but his son's son or daughter's son are considered like another, for his mind is not so close to them. And a mother who transfers ownership to her fetus, he acquires just like a father who transferred ownership [Shevut Yaakov].

One who transferred ownership of a portion of his property to an animal or to one who has not yet come into the world, and then went back and said to his fellow, "Acquire like this animal" or "like this fetus," he has said nothing. For since he made it dependent upon one who has no legal capacity for acquisition, he too does not acquire, and we say that this was his intention: just as the animal did not acquire, you too shall not acquire. However, if he said to his fellow, "You and the animal acquire my property," or "You and the fetus," he acquires half. Even though he transferred them in a single act of acquisition, nevertheless, since he did not make them dependent upon one another, we divide his speech. And so too, if he said to his son, "You and my fetus that my wife shall conceive from me acquire," the son who is born takes half at the outset, and afterwards when the father dies, he and the fetus divide the second half by way of inheritance, for his gift regarding the fetus is nothing since she is not pregnant. And just as there is no acquisition for one who has not yet come into the world regarding a gift, so too he has no acquisition regarding a lien. However, one can transfer ownership even to the fetus of another through "acquire in order to transfer ownership," where he says to one person, "Acquire now in order to transfer ownership to the fetus of so-and-so when it is born," for this is like a condition, and a condition can be stipulated in any manner, as I wrote in siman 209 [Beit Yosef]. And there is one who says that even regarding his son, he does not grant acquisition to a fetus except for movable property and not for lands [Nimukei Yosef chapter 9]. And just as there is no acquisition for a fetus, so too there is no acquisition for a dead person, for he is not a subject of acquisition. Nevertheless, one who transfers something to a dead person that is for the needs of his burial and his honor, they must do for him everything that was obligated on his behalf; and see what I wrote in siman 203, section 8 [what the Ketzot HaChoshen wrote in the name of the Mordechai in the chapter "Mi Shemet," we have already explained there, and there is no need for his forced interpretation, and examine it carefully].

It appears to me that just as we say regarding an acquisition of that which has not yet come into the world that for his son he transfers with a full heart, so too regarding that which has not yet come into the world, or that which is not in his possession, or that which lacks substance, where we say that when he reserved for himself he reserved generously, as has been written in siman 209 section 17 and in siman 212 section 4, so too when he reserved for his son or for his daughter we say as well that he reserved generously. And that which we wrote in siman 209, that for heirs he did not reserve generously, that refers to other heirs and not to his offspring [and a proof for this is from Bava Batra 63a; however, according to what I wrote there in siman 212 there is no proof, and delve into this].