No. As a result, he had a sin named after him—the Sin of Onan. Onan knew that any children he had with Tamar would not be his, so “he spilled his semen on the ground whenever he went in to his brother’s wife, so that he would not give offspring to his brother.” (NSRV; Genesis 38:9) The Lord put Onan to death as well. For years, the Sin of Onan was used as an injunction against masturbation. However, most modern scholarship contends that what Onan practiced was not masturbation, but coitus interruptus.