Genesis 38:9-11

9But Onan knew that the seed would not be his. So every time he went to his brother’s wife he would destroy it on the ground so as not to provide a seed for his brother.

10What he did was evil in Adonai’s eyes, so He put him to death also.

11Then Judah said to his daughter-in-law Tamar, “Stay as a widow in your father’s house until my son Shelah grows up,” because he thought, “Otherwise he too might die, like his brothers.” So Tamar went and stayed in her father’s house.