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

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

But Onan knew that the offspring would not be his, so whenever he slept with his brother’s wife, he released his semen on the ground so that he would not produce offspring for his brother.

Judah’s sons: Er, Onan, Shelah, Perez, and Zerah; but Er and Onan died in the land of Canaan.
Perez’s sons: Hezron and Hamul.

Judah’s sons included Er and Onan, but they died in the land of Canaan.

Judah’s sons: Er, Onan, and Shelah. These three were born to him by Bath-shua the Canaanite woman. Er, Judah’s firstborn, was evil in the Lord’s sight, so He put him to death.