Leviticus 15:16-18 states the following:
16 “‘When a man has an emission of semen, he must bathe his whole body with water, and he will be unclean till evening. 17 Any clothing or leather that has semen on it must be washed with water, and it will be unclean till evening. 18 When a man has sexual relations with a woman and there is an emission of semen, both of them must bathe with water, and they will be unclean till evening.
Upon an initial reading of this passage, one could wondering whether it, at least in some way, suggests that masturbation is a sin. After all, it does explicitly state that a man’s having an emission of semen is something that makes him “unclean.” In the New Testament the idea of something being unclean may carry connotations of sinfulness. Clearly, God cares about the issue enough to declare such a man unclean.
However, upon closer inspection of this passage we notice a number of things. First of all, the passage does not clearly refer to masturbation so much as the unconscious emission of semen in v 16 and the emission of semen in the context of intercourse. Second of all, even if v 16 does refer to masturbation, the way that a person is to deal with such is the exact same way that a person must deal with participating in the God-given act of sexual intercourse between a husband and a wife – by being unclean until evening and bathing in water. Essentially, God is simply saying that when one has religious duties, sexual intercourse is not permitted. The same message can be found in other texts of scripture (see Exodus 19:15, Leviticus 22:4, Deuteronomy 23:10-11, 1 Samuel 21:5, and 2 Samuel 11:11). Finally, and most importantly, there is no need for an animal sacrifice to atone for the uncleanness mentioned in this passage. Most other unclean acts require a sacrifice in this same chapter of scripture, but not in the case of v 16. In fact, one’s being unclean does not mean that such a person has committed a sin – remember, women were considered unclean just through the uncontrollable experience of their own menstrual cycles – uncleanness does not equal sin. In this case, it seems clear that the uncleanness is a ceremonial uncleanness and nothing more.
Thus, regardless of whether the emission of semen in v 16 comes about through conscious masturbation or unconscious nocturnal emissions, the uncleanness is ceremonial in nature and clearly does not refer to something sinful. This, however is not to say that the practice of masturbation is not sinful, but just to say that the practice is not shown to be sinful in this passage. Take a look at some of the scientifically proven dangers of masturbation.