Genesis 38:9-11

9Onan knew that the 12offspring would not be his; so when he went in to his brother’s wife, he 3wasted his seed on the ground in order not to give 4offspring to his brother. 10But what he did was displeasing in the sight of the Lord; so He 5took his life also. 11Then Judah said to his daughter-in-law Tamar, “6Remain a widow in your father’s house until my son Shelah grows up”; for he 7thought, “I am afraid that he too may die like his brothers.” So Tamar went and lived in her father’s house.