Judah acquired a wife for Er his firstborn; her name was Tamar.

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

Then Judah said to his daughter-in-law Tamar, “Live as a widow in your father’s house until Shelah my son grows up.” For he thought, “I don’t want him to die like his brothers.” So Tamar went and lived in her father’s house.

Then they attacked En Mishpat (that is, Kadesh) again, and they conquered all the territory of the Amalekites, as well as the Amorites who were living in Hazazon Tamar.

After three months Judah was told, “Your daughter-in-law Tamar has turned to prostitution, and as a result she has become pregnant.” Judah said, “Bring her out and let her be burned!”

Then Judah said to Onan, “Have sexual relations with your brother’s wife and fulfill the duty of a brother-in-law to her so that you may raise up a descendant for your brother.”

But Onan knew that the child would not be considered his. So whenever he had sexual relations with his brother’s wife, he withdrew prematurely so as not to give his brother a descendant.

He turned aside to her along the road and said, “Come on! I want to have sex with you.” (He did not realize it was his daughter-in-law.) She asked, “What will you give me in exchange for having sex with you?”

Judah recognized them and said, “She is more upright than I am, because I wouldn’t give her to Shelah my son.” He did not have sexual relations with her again.

So she removed her widow’s clothes and covered herself with a veil. She wrapped herself and sat at the entrance to Enaim which is on the way to Timnah. (She did this because she saw that she had not been given to Shelah as a wife, even though he had now grown up.)