Genesis 38:9-11

Revised Standard Version

⁹ But Onan knew that the offspring would not be his; so when he went in to his brother’s wife he spilled the semen on the ground, lest he should give offspring to his brother. ¹⁰ And what he did was displeasing in the sight of the Lord, and he slew him also. ¹¹ Then Judah said to Tamar his daughter-in-law, “Remain a widow in your father’s house, till Shelah my son grows up”—for he feared that he would die, like his brothers. So Tamar went and dwelt in her father’s house.