Leviticus 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). 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).

וְכׇל־הַנֹּגֵ֗עַ בְּכֹל֙ אֲשֶׁ֣ר יִהְיֶ֣ה תַחְתָּ֔יו יִטְמָ֖א עַד־הָעָ֑רֶב וְהַנּוֹשֵׂ֣א אוֹתָ֔ם יְכַבֵּ֧ס בְּגָדָ֛יו וְרָחַ֥ץ בַּמַּ֖יִם וְטָמֵ֥א עַד־הָעָֽרֶב׃

And whoever touches anything that was under him shall be unclean until evening: and he that bears any of those things shall wash his clothes, and bathe himself in water, and be unclean until evening.