Ramban (Nachmanides) on the Torah

V’LO THISOV NACHALAH’ (SO SHALL NO INHERITANCE) OF THE CHILDREN OF ISRAEL MOVE FROM TRIBE TO TRIBE. Scripture was only concerned to improve the situation at that time [i.e., for the daughters of Zelophehad who had raised that problem]. For if there were [then] women in Israel [already] married to [men of] another tribe, and they [the women] inherited [a portion of the Land] at that time, or would inherit at some future time if their brothers or fathers died without sons, their inheritance would perforce move from one tribe to another [because their husbands, who were of a different tribe, or their sons, would inherit them when they died], and who can straighten out in time what they have made crooked! The Torah, furthermore, did not want to command that the sons or husbands of these women should not inherit them [if they were not of the same tribe], because it did not deem it fit to abrogate [in this case] the [regular] law of inheritance. Similarly Scripture did not concern itself with events which would occur in the future; for even if those daughters who do not possess an inheritance [before they are married] would be permitted to marry [men from] any of the tribes, yet it is possible that at some future time they might inherit some property, if [all] their brothers die in the lifetime of their father, and thus their father’s inheritance, or that of their relatives would pass on to them. But according to the opinion of our Rabbis who interpreted: “This law — that they marry men of their father’s tribe. only applies to that particular generation,” it is possible etc. (see text) — (Kur Zahav, in the name of Aboab). that [at that time] there were no daughters who inherited a portion amongst all those who were to come into the Land [of Israel] except for the daughters of Zelophehad, and therefore [we do not find that] they [i.e., other women] asked [Moses about it as the daughters of Zelophehad did]. Scripture, then, is commanding that if anyone dies from that day onwards until the Land is divided up amongst their tribes, and his daughter inherits him, she should not marry [anyone] from another tribe, in order that when the Land is divided up, that man should not come to take himself an inheritance amongst another tribe. For the [Torah’s] concern about them [i.e., about the separate inheritance of each tribe] was greater at the time of the division of the Land [than afterwards], so that the [different] tribes should not become mixed up with each other when taking their inheritance, whereas afterwards their [separate] inheritance will have already become known, and they would not be so concerned about it. But since the [exact] time of the division [of the Land] was not yet known, He imposed the prohibition on the whole of that generation. And G-d in Whose hand is the soul of every living thing knew that “until the division of the Land no man would die without leaving a son, so that his daughters would be inheriting him” (Aboab). But such an assurance could naturally not apply if we were to say that the prohibition was for all generations. did not have to be concerned with future events [which might in certain cases result in the transfer of a particular inheritance from one tribe to another]. This explanation is correct according to the plain meaning of Scripture, for [the phrase in Verse 9] v’lo thisov nachalah is not a reason [for prohibiting the marriage of a woman who has already an inheritance, with a man from another tribe] “in order that the inheritance shall not be moved [from tribe to tribe],” but there are two separate commandments [in this section]. He commanded [first, in Verses 6-8] that those women who already possess an inheritance [such as the daughters of Zelophehad, who were not married] should only marry into their father’s tribe, and then [in Verse 9] He commanded that [in the case of] those who are already married [to men of other tribes and have no inheritance], or [in the case of all those women] who will come into an inheritance [later on] after they marry a man [of another tribe], the inheritance shall not move from one tribe to another tribe, but their brothers or their relatives are to inherit them, and not their sons or their husbands. Thus at first [in Verses 6-7] He commanded [the law] in connection with the daughters of Zelophehad, and afterwards [in Verse 8] concerning every daughter that possesseth an inheritance; and then He said in connection with all Israel that an inheritance shall not move from one tribe to another tribe [as stated in Verse 9, meaning] that even in the case of women who are [already] married [to men of another tribe], or [unmarried] women who have been commanded [not to marry men of another tribe] and who transgress this commandment, the men of their tribes [i.e., the women’s brothers or other relatives] should inherit them, in order that they should be closely attached to the inheritance of their fathers’ tribes, and their inheritance should not be severed from them, nor they from the inheritance of their fathers. And all these [restrictions] applied only to the generation which took possession of the Land, at the time that it was divided up. Thus He advised them about unmarried women, concerning whom they had asked, and He also made provision for those that were already married.
Thus is completed the Book of the Censuses [i.e., the Book of Numbers] and the standards of the hosts; And to G-d, the G-d of hosts, be praises and thanksgivings, in hundreds, thousands, and myriads. And as He has done for our ancestors great and awesome deeds, may He bring about speedily in our days the end of the wonders. May He build the House and the chambers and the border before the cells. And prepare there the thrones of the house of David, and may our eyes behold it! And may He in His mercies purify us of all [our] hidden [faults] and all errors,, 19:13. And show us wondrous things from His Torah!, 119:18. Amen. May His Will be so! Finished and completed.