Genesis 38:1-4

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 as a wife and had relations with her.

And she conceived and gave birth to a son, and he named him Er.

Then she conceived again and gave birth to a son, and she named him Onan.