Leviticus 15:7

And he that toucheth the flesh of him that hath the issue shall wash his clothes, and bathe himself in water, and be unclean until the even.

Cross-reference

Leviticus 11:25 prescribes identical washing and uncleanness-until-evening for touching dead animal carcasses, paralleling Leviticus 15:7 for touching a person with discharge.

Leviticus 11:39 repeats the same rule for touching a dead edible animal as Leviticus 15:7 does for touching a person with discharge.

Leviticus 22:5 forbids priests from touching anyone with uncleanness, alluding to the specific case of a person with discharge in Leviticus 15:7.