Genesis 38:1-6

And it came about at that time, that Judah departed from his brothers and visited a certain Adullamite, whose name was Hirah. Judah saw there a daughter of a certain Canaanite whose name was Shua; and he took her and went in to her. So she conceived and bore a son and he named him Er. Then she conceived again and bore a son and named him Onan. She bore still another son and named him Shelah; and it was at Chezib that she bore him. Now Judah took a wife for Er his firstborn, and her name was Tamar.