Genesis 38:1-6

At that time, Judah left his brothers and went down to stay with a man of Adullam named Hirah. There Judah met the daughter of a Canaanite man named Shua. He married her and made love to her; she became pregnant and gave birth to a son, who was named Er. She conceived again and gave birth to a son and named him Onan. She gave birth to still another son and named him Shelah. It was at Kezib that she gave birth to him. Judah got a wife for Er, his firstborn, and her name was Tamar.