Halakhah sur Les Nombres 35:34

Sometimes the reasons for commandments are similar to negative commandments and are thought of as being included in that which should be counted by itself. And this is like its stating, "Then the first husband who sent her away shall not take her to wife again [...] you must not bring sin upon the land" (Deuteronomy 24:4): Its stating, "you must not bring sin upon the land," is the reason for the prohibition that preceded it. It is as if it is saying that if you do this, you will cause great loss to the land. An it is [also] like its stating, "Do not profane your daughter and make her a harlot, lest the land fall into harlotry" (Leviticus 19:29). For its stating, "lest the land fall into harlotry," is the reason. It as if it said that the reason of this prohibition is so that "the land not fall into harlotry." And so too, its stating, "you shall not make yourselves unclean therewith and become unclean with them" (Leviticus 11:43): After mentioning the prohibition of the various species that are forbidden to eat, it gave a reason for this and said, "you shall not make yourselves unclean" by eating them. It is as if it is saying that which caused this to be prohibited is the making of oneself impure. And to explain that which He, may He be blessed, said after He prefaced not taking ransom from a murderer, "You shall not defile the land" (Numbers 35:34) - they said in the Sifrei (Sifrei Bamidbar 160:13), "The verse is telling us that spilling blood defiles the land." Hence behold it is clear that this negative statement is the reason for the previous negative commandment, not something else. And likewise regarding that which is stated, "He shall not go outside the sanctuary and not profane" (Leviticus 21:12) - if he does go outside, he profanes. And someone besides us already erred about this principle as well, and counted all of these [as] negative commandments, without observation. However whoever counted them will be embarrassed when they ask him and say, "What thing does this negative commandment prohibit?" And he will not have anything to answer at all. So through this, it becomes clear that it is not be counted. And this is what we intended to clarify about this principle.