פירוש על דברים 21:16

LO YUCHAL’ [literally: “he could not” but rendered: HE MAY NOT] DECLARE THE SON OF THE BELOVED FIRSTBORN. This is an admonition⁸²Since Rambam did not enumerate it in his Sefer Hamitzvoth as a separate negative commandment, because he included it as part of the specific laws relating to the commandment of inheritance, Ramban points out that, in his opinion, it is to be considered as a separate prohibition. See “The Commandments,” Vol. II, p. 336, Commandment 12. In the following two cases Rambam also admits that they are to be counted as separate commandments. against doing so. Likewise are all such verses as: ‘Lo thuchal’ (thou mayest not) eat within thy gates etc.;⁸³Above, 12:17. Literally: “thou couldst not.” So also in the following verse. ‘lo thuchal’ (thou mayest not) put a foreigner over thee.⁸⁴Ibid., 17:15. And in all these cases, Onkelos translates “you have no right” [which proves that the verse before us, too, constitutes an admonition], and the purport of these expressions is, “you could not allow yourself the possibility of doing so,” emphasizing the importance of the admonitions. Similarly, But he shall acknowledge the firstborn, the son of the hated, by giving him a double portion⁸⁵Verse 17. constitutes a positive commandment that he bequeath a double portion to the firstborn. Thus he who equalizes the firstborn with his brothers [i.e., he assigns him a share equal to theirs] violates both a negative commandment and a positive commandment, even though his words are not legally valid. He surely violates both [commandments] if, knowing he [the son of the hated one] is the firstborn, and did not wish to make it known that he is the firstborn and claimed that he is an ordinary son and caused him to inherit like any one of his sons. Now, these are newly-declared commandments. And from that which Scripture states [he may not declare the son of the beloved firstborn] in the face of the firstborn, the son of the hated it would appear to me that this commandment and this law are binding only during the lifetime of the firstborn. But, if the firstborn died during the life of his father, even though he [the deceased son] inherits his share as the firstborn in the grave and bequeathes it by law to his children, yet if the father wished [to deviate] and said, “My sons shall inherit such-and-such of my belongings, and the children of my [late] son, the firstborn, shall take such-and-such of my belongings,” his instructions are valid just as they would be valid in a case where there is no firstborn son. Similarly, the father would not be violating this negative commandment if he did not acknowledge the firstborn son only after his death, for I have never found the expression ‘al pnei’ (in the face of) except with reference to the living, such as: ‘al pnei’ (in the presence of) Aaron their father;⁸⁶Numbers 3:4. ‘al pnei’ (in the presence of) his father Terah,⁸⁷Genesis 11:28. and similarly all such expressions. [Therefore, in this case, since it states that the father may not do it ‘al pnei’ the firstborn of the hated, it follows that the prohibition is binding only during the lifetime of the firstborn and that the father had acknowledged him as such.].

לא יוכל לבכר את בן האהובה על פני בן השנואה הבכור. The firstborn son’s entitlement to an extra share in his father’s inheritance must not be transferred on account of his father loving his mother more or “hating” her, i.e. loving her less than his second wife. If the reason the father wants to transfer the extra portion of the inheritance away from the chronologically entitled son due to that son’s misconduct¸ this is in order, as we know from Baba Batra 133 אם לא היה נוהג כשורה זכור לטוב, íf the chronologically oldest did not conduct himself properly his inheritance may be transferred to another better one. [opinion of Rabbi Shimon ben Gamliel only, not accepted by codifiers. Ed.] It appears that this is what Yaakov did when he took birthright privileges away from Reuven (Chronicles I 5,1) transferring it to Joseph.

הנחילו את בניו, את אשר יהיה לו, when he allocates the inheritance to the sons he has, etc. The Torah did not write ביום אשר הנחילו את אשר יהיה, לו את בניו, "on the day he allocates his inheritance to the ones who are his, i.e. his sons," which would have been far more appropriate, because the Torah wanted the word הנחילו to appear next to את בניו. This is an allusion to what we learned in Baba Batra 130 that a father may allocate to one of his sons [because he is his natural heir. Ed.] more than would be his share if all the children would inherit equally when no special allocation has been made.