Genesis 38:9-11

American Standard Version

⁹ And Onan knew that the seed would not be his; and it came to pass, when he went in unto his brother’s wife, that he spilled it on the ground, lest he should give seed to his brother. ¹⁰ And the thing which he did was evil in the sight of Jehovah: and he slew him also. ¹¹ Then said Judah to Tamar his daughter-in-law, Remain a widow in thy father’s house, till Shelah my son be grown up; for he said, Lest he also die, like his brethren. And Tamar went and dwelt in her father’s house.