創世記38，8～9。 ユダはオナンに言った。「兄嫁のところに入り、兄弟の義務を果たし、兄のために子孫をのこしなさい」。オナンはその子孫が自分のものとならないのを知っていたので、兄に子孫を与えないように、兄嫁のところに入る度に子種を地面に流した。
英文は Then Judah said to Er`s brother Onan, "Go and sleep with your brother`s widow. Fulfill your obligation to her as her husband`s brother, so that your brother may have descendants." But Onan knew that the children would not belong to him, so when he had intercourse with his brother's widow, he let the semen spill on the ground, so that there would be no children for his brother.
オナンはオナニーの語源だと思っていたが、実は膣外射精だったのにゃ。
