The prohibition of extracting semen in vain (in Hebrew: הוצאת זרע לבטלה) is (according to Orthodox Judaism) a Biblical prohibition derived from (Genesis 38:7), this is explained in the midrash and Talmud. (A Rabbinical prohibition is different from a Biblical prohibition which is explained in the Oral Torah.) The prohibition forbids a male from intentional wasteful spilling of his semen. Unintentional wasting of seed is also a (lesser) sin according to the Oral Torah. Biblical sources The Hebrew Bible does not explicitly prohibit masturbation. Maimonides stated that the Tanakh does not explicitly prohibit masturbation. Jacob Milgrom acknowledged that while the rabbis condemned masturbation, "it is their enactment, not that of Scripture." states that any male who emits semen is considered ritually impure - whether the emission came through masturbation, nocturnal emission, or sex between married heterosexual partners. The traditional rabbinical interpretation of Leviticus 15 was that it applies to all sperm flows, including sperm flows due to masturbation. Other than this ritual impurity, no consequences or punishments are specified. The Biblical story of Onan () was interpreted by many later commentators as a source for prohibiting ejaculation outside a woman's body, including masturbation. In the story, Onan did not want to impregnate his wife (because, this being a levirate marriage, the resulting child would be considered to belong to Onan's brother Er rather than Onan), so when they had sex Onan performed coitus interruptus and caused his semen to spill on the ground. Onan was slain by God, which was deemed retribution for being "evil in the sight of the Lord" and disobeying a direct order from the Lord by being unwilling to father a child by his widowed sister-in-law. Nevertheless, opinions differ on whether his sin was denying a child to Er (which would have no implications for masturbation) or ejaculating outside the context of sex (implying that masturbation too is a sin) or both. The halakhic prohibition on masturbation Traditional rabbinic sources strictly prohibit male masturbation, and even activities which can lead to sexual arousal and thus ejaculation. The Mishnah states that if a man frequently touches his penis with his hand (in order to check for ritually impure emission), his hand "ought to be cut off". The Babylonian Talmud prohibits "emitting seed in vain", a term generally (but not only) referring to masturbation: The same passage likens the act to murder and idolatry, and also prohibits a