Genesis 38:9-13

Now Onan knew that the child would not be his; so when he had relations with his brother’s wife, he wasted his seed on the ground so that he would not give a child to his brother.

But what he did was displeasing in the sight of the Lord; so He took his life also.

Then Judah said to his daughter-in-law Tamar, “Remain a widow in your father’s house until my son Shelah grows up”; for he thought, “I am afraid that he too may die like his brothers.” So Tamar went and lived in her father’s house.

Now after a considerable time Shua’s daughter, the wife of Judah, died; and when the time of mourning was ended, Judah went up to his sheepshearers at Timnah, he and his friend Hirah the Adullamite.

And Tamar was told, “Behold, your father-in-law is going up to Timnah to shear his sheep.”