Masturbation

Genesis 38’s story of Onan has supplied the standard proof text against masturbation for centuries, but the passage is about a levirate-marriage obligation Onan refuses to fulfill, not about solitary sex — he withdraws during intercourse with his deceased brother’s widow to avoid giving her a child, and the text’s condemnation targets that refusal, not the act of ejaculation itself. Leviticus does treat nocturnal emission as a source of ritual impurity requiring purification, but impurity in that system is not equivalent to sin, and no biblical text extends that impurity logic into an explicit prohibition on masturbation.

That silence becomes conspicuous once you notice what the Hebrew Bible does bother to regulate: prohibited sexual unions, defined by who may have sex with whom, almost always framed around penetrative acts involving a penis. If the underlying concern were wasted reproductive potential, as some later interpreters have argued about prohibitions on same-sex intercourse, masturbation would be the most obvious target to prohibit outright — and it goes unmentioned. The gap left by that silence got filled centuries later, most acutely in 20th-century Mormonism, where the practice moved from a non-issue to a moral crisis freighted with the same stakes as murder, with real consequences for kids raised inside that framework.