Leviticus 15:1-4

The Lord also spoke to Moses and to Aaron, saying,

“Speak to the sons of Israel, and say to them, ‘When any man has a discharge from his body, his discharge is unclean.

This, moreover, shall be his uncleanness in his discharge: it is his uncleanness whether his body allows its discharge to flow or whether his body obstructs its discharge.

Every bed on which the man with the discharge lies becomes unclean, and everything on which he sits becomes unclean.