Genesis 38:11-19

Then Judah said to his daughter-in-law Tamar, “Live as a widow in your father’s house until my youngest son Shelah grows up.” So Tamar went home to her parents, but Judah worried that Shelah would end up dead like his brothers. After some time passed, Judah’s wife, the daughter of Shua, died. When his time of mourning was over, he and his friend Hirah the Adullamite went to Timnah to enjoy the festivities at the sheep-shearing. Meanwhile, Tamar had learned that Shelah had grown up, but Judah had still not given him to her to father a child for her deceased husband. So, when Tamar found out her father-in-law was coming to Timnah for the sheep-shearing, she removed her widow’s clothes and covered herself with a veil to disguise herself. And she sat waiting at the crossroads where Judah would have to pass by. When Judah saw her, she was wearing a veil over her face, so he thought she was a prostitute. He had no clue that she was his own daughter-in-law. So he approached her and said, “Come sleep with me.” “What will you give me if I do?” she answered. He responded, “I will send you a young goat from the flock.” “What guarantee can you give me that you will really send it?” she asked. “Well, what pledge do you want?” Judah asked. Tamar answered, “Give me your necklace with your personal signet and the staff you’re holding.” So, he gave them to her, and he went and slept with her. When she got up and went home, she removed her veil and put her widow’s garment back on. Later, she discovered she was pregnant.