Leviticus 15:2-4

New Century Version

² “Say to the people of Israel: ‘When a fluid comes from a person’s body, the fluid is unclean. ³ It doesn’t matter if the fluid flows freely or if it is blocked from flowing; the fluid will make him unclean. This is the way the fluid makes him unclean:

⁴ “‘If the person who discharges the body fluid lies on a bed, that bed becomes unclean, and everything he sits on becomes unclean.