Commentaire sur Le Lévitique 15:10

וכל הנגע בכל אשר יהיה תחתיו AND WHOSOEVER TOUCHETH ANYTHING THAT WAS תחתיו — under the זב. This intends to teach regarding such an object for riding upon (if a זב has ridden on it) that whoever touches it becomes unclean, but he does not require washing of clothes and this is something stricter in the case of a thing for sleeping on than in that of a thing for riding on (since the former necessitates that his garments should be washed; cf. v. 5).

[Beneath] the zov. I.e., not beneath “anything used for riding” which is juxtaposed to this phrase. Rather, it refers to the zov — that is, [a pure person who] touches the saddle that was underneath the zov, becomes impure but he does not require washing clothes.

והנושא אותם AND HE THAT BEARETH THEM — “them” means all that have been mentioned in the matter of a זב — his flow, his spittle, his semen, and his urine, and that upon which he has slept or ridden — the bearing of them makes a man unclean so that he in turn makes his garments unclean (cf. Sifra, Metzora Parashat Zavim, Chapter 4 4).