Nocturnal emission
Nocturnal emissions are mentioned in the bible in Deuteronomy 23:10 and Leviticus 15:16. Deuteronomy 23:10 says, "If any man among you becomes unclean because of a nocturnal emission, he must leave the camp and stay outside. 11When evening approaches, he must wash with water, and when the sun sets he may return to the camp." (Berean Standard Bible)