Not as if this was in itself a sin, but only a punishment of sin; though ofttimes it was sinful, as being a fruit of a man's intemperance and immoderate lust. See Leviticus 14:12.
Related Commentaries of Leviticus 15:15
Leviticus 15:15
15 And the priest shall offer them, the one for a sin offering, and the other for a burnt offering; and the priest shall make an atonement for him before the LORD for his issue.