Genesis 38:7

3 So she conceived and gave birth to a son, and Judah named him Er.

4 Again she conceived and gave birth to a son, and she named him Onan.

5 Then she gave birth to another son and named him Shelah; it was at Chezib that she gave birth to him.

6 Now Judah acquired a wife for Er, his firstborn, and her name was Tamar.

7 But Er, Judah’s firstborn, was wicked in the sight of the LORD; so the LORD put him to death.

8 Then Judah said to Onan, “Sleep with your brother’s wife. Perform your duty as her brother-in-law and raise up offspring for your brother.”

9 But Onan knew that the offspring would not belong to him; so whenever he would sleep with his brother’s wife, he would spill his seed on the ground so that he would not produce offspring for his brother.

10 What he did was wicked in the sight of the LORD, so He put Onan to death as well.

11 Then Judah said to his daughter-in-law Tamar, “Live as a widow in your father’s house until my son Shelah grows up.” For he thought, “He may die too, like his brothers.” So Tamar went to live in her father’s house.

Read all of Genesis 38