3 The sons of Judah: Er, Onan, and Shelah. These three were born to him by Bath-shua the Canaanite. Er, Judah’s firstborn, was wicked in the sight of the LORD, who put him to death.
1 Chronicles 2:3 Cross References - MSB
Genesis 38:2-10
2 There Judah saw the daughter of a Canaanite man named Shua, and he took her as a wife and slept with her.
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.
Genesis 46:12
12 The sons of Judah: Er, Onan, Shelah, Perez, and Zerah; but Er and Onan died in the land of Canaan. The sons of Perez: Hezron and Hamul.
Numbers 26:19
19 The sons of Judah were Er and Onan, but they died in the land of Canaan.
1 Chronicles 9:5
5 From the Shilonites: Asaiah the firstborn and his sons.