Genesis 38:6-19

Now Judah took a wife for Er his firstborn; her name was Tamar. But Er, Judah’s firstborn, was evil in the sight of the LORD, and the LORD killed him [in judgment]. Then Judah told Onan, “Go in to your brother’s widow, and perform your duty as a brother-in-law [under the levirate marriage custom]; [be her husband and] raise children for [the name of] your brother.” [Deut 25:5-10] Onan knew that the child (heir) would not be his [but his dead brother’s]; so whenever he lay with his brother’s widow, he spilled his seed on the ground [to prevent conception], so that he would not give a child to his brother. But what he did was displeasing in the sight of the LORD; therefore He killed him also [in judgment]. Then Judah said to Tamar, his daughter-in-law, “Remain a widow at your father’s house until Shelah my [youngest] son is grown”; [but he was deceiving her] for he thought that [if Shelah should marry her] he too might die like his brothers did. So Tamar went and lived in her father’s house. But quite a while later, Judah’s wife, the daughter of Shua, died; and when the time of mourning was ended, he went up to his sheepshearers at Timnah with his friend Hirah the Adullamite. Tamar was told, “Listen, your father-in-law is going up to Timnah to shear his sheep.” So she removed her widow’s clothes and covered herself with a veil, and wrapped herself up [in disguise], and sat in the gateway of Enaim, which is on the road to Timnah; for she saw that Shelah had grown up, and she had not been given to him as a wife [as Judah had promised]. When Judah saw her, he thought she was a [temple] prostitute, for she had covered her face [as such women did]. He turned to her by the road, and said, “Please come, let me lie with you”; for he did not know that she was his daughter-in-law. And she said, “What will you give me, that you may lie with me?” He answered, “I will send you a young goat from the flock.” And she said, “Will you give me a pledge [as a deposit] until you send it?” He said, “What pledge shall I give you?” She said, “Your seal and your cord, and the staff that is in your hand.” So he gave them to her and was intimate with her, and she conceived by him. Then she got up and left, and removed her veil and put on her widow’s clothing.