There are many commentators that invoke the story of Onan as a source for the prohibition behind onanism, but there seems to be a distinctly different issue going on that is "evil in the eyes of Hashem."

Ordinarily, the former wife of your brother through widowhood would be expressly forbidden. It is only due to the positive mitzvah of yibum that the kum aseh is docheh the lo sa'aseh because we are commanded "lehakim zera le'achiv." Onan engaged in the "act" of yibum, yet it is expressly stated in the Torah that he engaged in coitus interruptus because he refused to fulfill this positive command. As such, he was not fulfilling the kum aseh and therefore there would BE no heter for him. Thus, Onan wasn't engaged in masturbation, but in an act of gilui arayos with eishes ach!

We find later in the Talmud that some Chachomim decreed that because we are concerned with the "purity of the intent" behind the act they prefer chalitzah over yibum, though this is one of the many splits between Asheknazim (following Rabbeinu Tam) and Sephardim (following Rambam). This would appear to directly mirror the incident with Onan.

Is there a source that interprets Onan's behavior in this manner - as a violation of gilui arayos due to his refusal to fulfill the heter of yibum?

  • 1
    Try Noda' Bihuda Kamma EH 54
    – Double AA
    Dec 22, 2016 at 14:36
  • 1
    your question assumes that the issur of eishes ach was a punishable (by God) offense at that time. I'm not sure why you would assume this, given that the commandment had not yet been given.
    – Jay
    Dec 22, 2016 at 14:52
  • He would assume this because there is a well known principle that the avos kept the torah. Dec 22, 2016 at 17:24
  • 1
    @ClintEastwood what does what they chose to do have to do with being obligatory and punishable? Also, we are not discussing the Avos.
    – Jay
    Dec 22, 2016 at 20:43
  • 2
    @IsaacKotlicky Actually eishes ach is not one of the sheva mitzvos according to most rishonim
    – Jay
    Dec 22, 2016 at 20:48

1 Answer 1


The basic answer to your question appears to be no. The meforshim do not connect the actions of Onan to aishes ach. One reason is that they explain the pesaukim as showing that both Er and Onan did the same aveirah. Thus, Er could not have been involved with aishes ach. Additionally, the discussion of Chazal about preferring chalitza rather than yibum does not invalidate the yibum. It is a matter of hashkafa. however, if the yibum had been done, it was valid and the isur of aishes ach does not apply.

Rashi points out that Er also deliberately refused to allow Tamar to become pregnant. This refusal to fulfill the mitzvah of pru u'rvu is what caused Hashem to punish him. Rav Hirsch connects this with the mitzvah of Pru U'Rvu

was evil in the eyes of the Lord: [His evil was] like the evil of Onan, viz. that he wasted his semen, as it is written in connection with Onan: “and He put him to death also,” meaning that, as Er’s death, so was Onan’s death. Now, why should Er waste his semen? So that she (Tamar) would not become pregnant and her beauty be impaired. [From Yev. 34b]

Onan committed the same sin (though for a different reason). That is, since any children that they might have would be called "children of Er", he refused to allow her to become pregnant. The first born child is treated as the child of the deceased brother. Thus, the child would have been treated as the heir of Er and not of Onana.

and raise up progeny: The son shall be called by the name of the deceased. [From Targum Jonathan ben Uzziel]

he wasted [his semen] on the ground: He practiced coitus interruptus. [From Gen. Rabbah 85:5]

Yibum and Chalitzah

The Torah dictates that if a married man dies childless, the widow is to marry her dead husband's brother, preferably the eldest. The firstborn son they produce together is considered a continuation of the dead husband's line.

  • interesting, what is here the significance of the "called by the name of the deceased"?
    – kouty
    Dec 23, 2016 at 5:18
  • @kouty The first born child is treated as the child of the deceased brother. Thus, the child would have been treated as the heir of Er and not of Onana Dec 23, 2016 at 16:29
  • I am familiar with this specific exposition of the possuk. My question was whether there were commentators that link this story to the concerns regarding improper yibum. Dec 24, 2016 at 23:16
  • @IsaacKotlicky Rav Hirsch connects it with Pru Urvu so that she does not have to specifically "marry". Dec 24, 2016 at 23:59
  • @IsaacKotlicky I have not seen anyone connecting it to Aishes Ach Dec 25, 2016 at 0:35

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .