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Michael L. Satlow





Does the Torah Prohibit Male Masturbation?



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Michael L. Satlow





Does the Torah Prohibit Male Masturbation?






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Does the Torah Prohibit Male Masturbation?

Onan son of Judah “would let [his seed] go to waste on the ground, so as not to provide offspring for his brother. This was wicked in the eyes of YHWH, who killed him” (Genesis 38:9–10). What was Onan’s sin?


Does the Torah Prohibit Male Masturbation?

Image: Unsplash/A. Nishaath, adapted using Dall-E,

In his halakhic compendium Kitzur Shulchan Arukh, R. Shlomo Ganzfried (1804–1886) describes the terrible sin of wasting male seed:

קיצור שלחן ערוך קנא אָסוּר לְהוֹצִיא זֶרַע לְבַטָלָה. וְעָוֹן זֶה חָמוּר מִכָּל עֲבֵרוֹת שֶׁבַּתּוֹרָה.
Kitzur Shulchan Arukh 151 It is prohibited [for men] to spill their seed in vain. And this is a graver sin than any other transgression in the Torah.[1]
וְאֵלּוּ שֶׁמְּנָאֲפִים בַּיָּד וּמוֹצִיאִים זֶרַע לְבַטָּלָה, לֹא דַי לָהֶם שֶׁאִסּוּר גָּדוֹל הוּא, אֶלָּא שֶהָעוֹשֶׂה זֹאת, הוּא בְנִדּוּי, וַעֲלֵיהֶם נֶאֱמַר, יְדֵיכֶם דָּמִים מָלֵאוּ, וּכְאִילּוּ הוֹרֵג אֶת הַנֶּפֶשׁ.
Those who masturbate (lit. “fornicate with the hand”) and spill their seed in vain, not only do they violate a serious transgression, but also one who does this is placed under a ban. Regarding such people, it is said (Isa 1:15), “Your hands are full of blood,” and it is akin to killing a person.[2]

Ganzfried then connects this sin with the biblical story of Er and Onan, in which Onan spills his seed:

וּרְאֵה מַה שֶּכָּתַב רַֹשִ"י בְּפָרָשַת וַיֵֹשֶב בְּעֵר וְאוֹנָן שֶׁמֵּתוּ בְּחֵטְא זֶה.
See what Rashi wrote in Parashat Vayeshev[3] concerning Er and Onan, who died because of committing this sin.[4]
וְלִפְעָמִים בְּעֹנֶשׁ זֶה, חַס וְשָׁלוֹם, בָּנָיו מֵתִים כְּשֶׁהֵם קְטַנִים, אוֹ שֶׁיִהְיוּ רְשָׁעִים, וְהוּא בָא לִידֵי עֲנִיוּת.
Sometimes, as a punishment—God forbid—one’s children die when they are young, or grow up to be wicked, while the sinner ends up living in poverty.


Jewish sources are not unique in connecting the story of Onan with masturbation. Indeed, in 1716, a new term “onanism” was coined to describe the sinful act in a pamphlet with the title: Onania, or the Heinous Sin of Self-Pollution, and All Its Frightful Consequences, in Both Sexes, Considered. With Spiritual and Physical Advice for Those Who Have Already Injur’d Themselves by This Abominable Practice. The pamphlet was republished multiple times and led to several spin-off books.[5]

And yet, while Jewish and Christian sources connect the biblical story of Onan with the sin of spilling seed, this has little to do with the simple meaning of the biblical account.

The Death of Er and Onan

Judah’s eldest son Er dies shortly after his marriage (Gen 38:6–7), without an heir. The ancient Israelite practice of levirate marriage (yibbum) required his brother, Onan, to marry his widow and to have a child that would carry on Er’s name.[6]

בראשית לח:ח וַיֹּאמֶר יְהוּדָה לְאוֹנָן בֹּא אֶל אֵשֶׁת אָחִיךָ וְיַבֵּם אֹתָהּ וְהָקֵם זֶרַע לְאָחִיךָ.
Gen 38:8 Then Judah said to Onan, “Join with your brother’s wife and do your duty by her as a brother-in-law, and provide offspring for your brother.”

Onan, however, objects to performing this service for his deceased brother, and thus engages in coitus interruptus:

בראשית לח:ט וַיֵּדַע אוֹנָן כִּי לֹּא לוֹ יִהְיֶה הַזָּרַע וְהָיָה אִם בָּא אֶל אֵשֶׁת אָחִיו וְשִׁחֵת אַרְצָה לְבִלְתִּי נְתָן זֶרַע לְאָחִיו. לח:י וַיֵּרַע בְּעֵינֵי יְ־הוָה אֲשֶׁר עָשָׂה וַיָּמֶת גַּם אֹתוֹ.
Gen 38:9 But Onan, knowing that the offspring would not count as his, whenever he lay with his brother’s wife, he would let [his seed] go to waste on the ground, so as not to provide offspring for his brother. 38:10 This was wicked in the eyes of YHWH, who took his life also.[7]

This is the only text in the Bible to discuss spilling seed, and even here, Onan’s sin is not the spilling of his seed per se, but his selfish unwillingness to have a child that “would not count as his.” This crime against his deceased brother, and against his family, leads YHWH to take his life.[8]

Second Temple Sources

The few Second Temple sources that speak about this story do not understand Onan’s sin as spilling seed either, but follow the simple meaning of the text, that he violated his familial obligation to produce an heir for his deceased brother.

Jubilees: Er and Onan Never Had Sex with Tamar

The 2nd century B.C.E. book of Jubilees retells the story of Er and Onan, describing Tamar as an Aramean woman—the Torah never gives her ethnic origin—and claims that Er hated her so much that he never slept with her:

Jub 41:1 In the forty-fifth jubilee, the second week during the second year [2165], Judah took as a wife for his first-born Er one of the Aramean women whose name was Tamar. 41:2 He hated (her) and did not lie with her because his mother was a Canaanite woman and he wanted to marry someone from his mother’s tribe. But his father Judah did not allow him. 41:3 That Er, Judah’s first-born, was evil and the Lord killed him.[9]

Jubilees continues with the account of Onan’s sin and punishment, changing his act from coitus interruptus to masturbation by saying that Onan entered “Tamar’s house” as opposed to Tamar:

Jub 41:4 Then Judah said to his brother Onan: “Go in to your brother’s wife, perform the levirate duty for her, and produce descendants for your brother.” 41:5 Onan knew that the descendants would not be his but his brother’s, so he entered the house of his brother’s wife and poured out the semen on the ground. In the Lord’s estimation, it was an evil act, and he killed him.[10]

Recasting Onan’s act as masturbation is not about making his behavior more sinful but—as Cana Werman of Ben Gurion University notes in her commentary (ad loc.)—to avoid the possibility that Judah would have sex with a woman that his sons had slept with, which is forbidden in the Torah.[11] Indeed, Werman notes, this is why Jubilees also adds the detail that Er hated Tamar and never slept with her.

Philo: Onan the Selfish

In his On the Posterity of Cain and His Exile (De Posteritate Caini) Philo, the Jewish philosopher in Alexandria (ca. 25 B.C.E.–ca. 50 C.E.) uses Onan as a paradigmatic example of someone who pursues only his one pleasure:

The chief representative of this doctrine is Onan, kinsman of the “leathery”[12] Er. For it says that this man “knowing that the offspring would not count as his, let [his seed] go to waste whenever he joined with his brother’s wife, so as not to provide offspring for his brother” (Gen 38:9), going beyond all bounds in love of self and love of pleasure.[13]

Philo continues by envisioning a lecture he would love to deliver to Onan if he could:

I should therefore address him thus: “Will you not”—so I would say to him—“by providing only your individual profit, be doing away with all the best things in the world, unless you are to get some advantage from them, honor paid to parents, loving care of a wife, bringing up of children, happy and blameless relations with domestic servants, management of a house, leadership in a city, maintaining of laws, guardianship of usages, reverence towards elders, respect for the memory of the departed, fellowship with the living, piety in words and actions towards the Deity?

For you are overturning and wasting all these, by breeding and nursing for yourself pleasure, the glutton and libertine, in whom all evil things have their origin.”

Philo does not condemn Onan for the non-procreative (or “wasteful”) emission of semen. Instead, it is the fact that Onan allows himself to enjoy being with his brother’s widow while spurning the familiar requirement to produce an heir for his deceased brother that Philo deems selfish.

Rabbinic Literature: The Sin of Er and Onan

In rabbinic texts, Onan’s sin is still understood as a refusal to produce an heir for his brother. Thus, Genesis Rabbah[14] (§85) glosses the verse with:

יהודה התחיל ביבום.... וידע אונן וגו' דש מבפנים וזורה מבחוץ וימת גם אותו.
Judah established the practice of levirate marriage… “and Onan knew etc.”, so he threshed inside and spread his seed on the outside, “and [God] killed him as well.”

Nevertheless, the rabbis extend the problem of “spilling seed” to birth control in general, by claiming that Er, Onan’s older brother, also refused to get Tamar pregnant.[15] The Torah never explains why YHWH finds Er to be bad and kills him:

בראשית לח:ו וַיִּקַּח יְהוּדָה אִשָּׁה לְעֵר בְּכוֹרוֹ וּשְׁמָהּ תָּמָר. לח:ז וַיְהִי עֵר בְּכוֹר יְהוּדָה רַע בְּעֵינֵי יְ־הוָה וַיְמִתֵהוּ יְ־הוָה.
Gen 38:6 Judah got a wife for Er his first-born; her name was Tamar. 38:7 But Er, Judah’s first-born, was displeasing to YHWH, and YHWH took his life.[16]

Genesis Rabbah (§85), however, explains that Er avoided having vaginal sex with Tamar, using the euphemism שהיה חורש בגגות “he would plow on the roofs.”

Midrash HaGadol, a 14th century collection of older midrashim, put together by the Yemenite sage, Rabbi David Adani, explains that Er did not want to get Tamar pregnant because she was beautiful (gloss on Gen 38:6):

אמרו תמר בת שם בן נח היתה והיתה נאה ביותר וכיון שנטלה ער אמר עכשו היא יולדת והיא מתכערת. מה עשה, היה מניח השדה וחורש בגגות. לשון נקי.
They said that Tamar was the daughter of Shem son of Noah,[17] and that she was exceedingly beautiful. Once Er married her, he said (to himself): “Now she will give birth and become unattractive.” What did he do? He abandoned the field and plowed on the roof—this is a euphemism.[18]
ועליו הוא אומר ואץ ברגלים חוטא (משלי יט, ב).
Regarding him it is said (Prov 19:2): “One who makes haste in the legs is a sinner.”[19]

The sin here is not the act spilling his seed in acts of non-penetrative sex, but refusing to get her pregnant.

Jerusalem Talmud: Filling Up and Pouring into Trash

Mishnah Ketubot 7:5 states that if a man forces his wife שֶׁתְּהֵא מְמַלְּאָה וּמְעָרָה לָאַשְׁפָּה “to fill up and pour into the trash,” she can demand a divorce and collect her ketubah payment. The Jerusalem Talmud (ad loc.) glosses this phrase:

תמן אמרין כגון מעשה ער ורבנין דהכא אמרין דברים של בטלה
There (in Babylonia) they say: “akin to the act of Er,” while the rabbis here (Palestine) say [he forces her to perform] “frivolous activities.”

In his Korban HaEdah commentary (ad loc.), Rabbi David Fränkel (1704–1762) explains the position of the Babylonian sages:

אף זה אומר לה לאחר שתשמש וימלא רחמה שכבת זרע תרוץ ברגליה ותנפצנו כדי שלא תקלוט הזרע ותתעבר
Similarly, her husband tells her after sex, when her womb is filled with semen, she should run around with her legs and scatter it, so that the semen does not take hold and she does not become pregnant.[20]

Again, the problem is Er is refusing to get his wife pregnant.

The Babylonian Talmud: Is Coitus Interruptus a Sin Per Se?

The Babylonian Talmud (Yebamot 34a–b) has a sustained discussion of the sin of Er and Onan, in a passage about whether a woman can become pregnant by her first act of intercourse.[21] Rav Nachman believes it is impossible, leading his student, Rava, to use Tamar as an example of such a woman, to prove that it is possible:

בבלי יבמות לד.–לד: אמר] ל[יה] רבא לרב נחמן: "והא תמר בביאה ראשונה איעבר?!"
b. Yeb 34a–34b Rava said to Rav Nachman: “But didn’t Tamar get pregnant from her first act of sex?”[22]

The Talmud predictably challenges the assertion that this was Tamar’s first time, she had been married to Er and then Onan:

והא הוו ער ואונן?
But wasn’t there Er and Onan?
שלא כדרכה שימשו.
They had non-vaginal (or anal) sex with her.[23]

This leads to a discussion of what makes this a sin.

The Talmud quotes a baraita[24] that while a man’s wife is nursing, he should only have non-procreative sex with her to ensure that she not get pregnant and thus cut off the milk supply to the nursing baby:

מתיבי: "כל עשרים וארבעה חדש דש מבפנים וזורה מבחוץ"—דברי ר' אליעזר. אמרו לו: "הללו אינן אלא כמעשה ער ואונן."
They brought this contradictory passage: “All 24 months [of nursing], he should thresh inside and spill outside”—these are the words of Rabbi Eliezer. [The Sages] said to him: “But this is the act of Er and Onan.”

Clearly, Rabbi Eliezer does not see the story of Onan as a precedent forbidding coitus interruptus, but the Sages do.[25] Yet, the final line of the sugyah implies that the real sin is not spilling seed but a man refusing to impregnate his wife:

בשלמ[א] א[ו]נן משום לא לו יהיה הזרע, אלא ער מאי טעמ[א] עבד הכי?
It makes sense that Onan did this, since he knew that the child would not be his, but Er, for what reason did he did it?
סבר שמא תתעבר ויכחיש יפיה.
He was worried lest she get pregnant and ruin her beauty.

Thus, even here, we do not yet a clear argument for the sinfulness of spilling seed per se, though by forbidding coitus interruptus even with nursing mothers it comes very close.

Masturbation: Onan and the Cause of the Flood

Kallah Rabbati (4th cent. Babylonia)[26] makes a literary connection between Onan’s sin and the sin of the flood generation:

כלה רבתי ב:ז תאנא: דור המבול כלן מוציאין שכבת זרע לבטלה היו.
Kallah Rabbati 2:7 It was taught: The generation of flood would all spill their seed in vain.

The reason given for this behavior is based on their desire to avoid having children:

הוו בהו אצטגניני, אמרי עלמא לא פחות משיתא אלפי שנין, לא נוליד, ואנן נחיה לעלמא כוליה, אמר להם הקדוש ברוך הוא, שמתם עצמכם עיקר, הריני עוקר שמיכם שלא תעלו בחשבון עולם.
They had astrologers among them who said “The world will last no less than 6,000 years. If we do not procreate, we will live for the entire span of the universe.” The Holy One, blessed be He said to them: “You imagine yourselves as the main (ʿiqar) thing. I will uproot (ʿoqer) your heavens so you will not be able to tell the age of the world.”

The text then offers the midrashic proof:

מנא הני מילי, דכתיב באונן (בראשית לח:ט) "והיה אם בא אל אשת אחיו ושחת ארצה", שהיה מחמם את עצמו ומוציא שכבת זרע לבטלה, וכתיב בדור המבול (בראשית ו:יב) "כי השחית כל בשר את דרכו על הארץ."
From where do we know this? For it says regarding Onan (Gen 38:9) whenever he lay with his brother’s wife, he would let [the semen] go to waste on the ground,” meaning he would arouse himself and spill his seed on the ground. And it says regarding the flood generation (Gen 6:12) “for all flesh wasted his way upon the ground.”

The midrash here builds on the similar expressions (in bold), and sees this sin as the cause of the flood.[27] This literary connection may also be behind Rabbi Eliezer’s (2nd cent. C.E.) enigmatic statement, recorded in the Babylonian Talmud:

בבלי נדה יג. רבי אליעזר אומר: "כל האוחז באמה ומשתין כאילו מביא מבול לעולם."
b. Niddah 13a Rabbi Eliezer says: “Anyone who holds his penis when he urinates, it is as if he brings a flood to the world.”

The statement is glossed by a 3rd century C.E. Galilean Amora later in the same passage:

בבלי נדה יג וכל כך למה? מפני שמוציא שכבת זרע לבטלה, דאמר רבי יוחנן: "כל המוציא שכבת זרע לבטלה חייב מיתה, שנ[אמר]: 'וירע בעיני ה' אשר עשה וימת גם אותו'".
b. Niddah 13a Why so severe? Because he will spill his seed in vain, as Rabbi Yohanan said: “Whoever spills his seed in vain deserves to die, as it says (Gen 38:10) ‘What he (Onan) did was wicked in the eyes of God, and He killed him as well.’”

Here we have a clear condemnation of seed spilling per se, including masturbation.[28]

Zoroastrian Influence?

The Babylonian Talmud and (the Babylonian) Kallah Rabbati’s emphasis reflects an a priori strong aversion to the waste of semen that makes sense in the cultural context of Zoroastrian Persia, which imputed demonic powers to semen, seeing it as a dangerous fluid that must be controlled (as echoed in b. Eruvin 18b).[29] For example, in the Vendidad, a Zoroastrian text from the rabbinic period, we read:

Vendidad 8:27 O Maker of the material world, though Holy One! If a man voluntarily emits his seed, what is the penalty for it? What is the atonement for it? What is the cleansing from it? Ahura Mazda answered: “For that deed, there is nothing that can pay, nothing that can atone, nothing that can cleanse from it; it is a trespass for which there is no atonement, for ever and ever.”

To be clear, the sources quoted in Kallah Rabbati and the Babylonian Talmud are said to be from sages in Roman Palestine. It is possible, of course, that the attribution is in error or fictive, but even if the attribution is accurate, it is significant that these readings survived only in Babylonian texts, not Palestinian texts, implying that they struck a chord in the former context as opposed to the latter.

Not a Biblical Problem

The concern over spilling seed become codified in medieval halakhic literature, and are expanded upon in kabbalistic literature, which, as quoted above in the Kitzur Shulchan Arukh sees the spilling of seed as the gravest of sins. And yet, this claim has no basis in the biblical story of Onan or any other biblical account.

In the Bible, Er’s sin is never mentioned, and Onan’s sin is his refusal to produce an heir for his deceased brother. Given that, a more accurate definition of “onanism” would be “marrying your brother’s widow but refusing to procreate with her,” but this would likely have less cachet than the 18th century attempt to connect the biblical story with the “heinous sin of self-pollution, and all its frightful consequences.”[30]


December 8, 2022


Last Updated

April 10, 2024


View Footnotes

Prof. Michael L. Satlow is Professor of Judaic Studies and Religious Studies at Brown University. He holds a Ph.D. from JTS, is the author of Creating Judaism: History, Tradition, Practice and How the Bible Became Holy and the editor of Judaism and the Economy: A Sourcebook. He maintains a blog at and can be followed on twitter at @mlsatlow.