3 The sons of Judah: Er, and Onan, and Shelah; which three were born unto him of Bath-shua the Canaanitess. And Er, Judah's first-born, was wicked in the sight of the LORD; and He slew him.
1 Chronicles 2:3 Cross References - JPS_ASV_Byz
Genesis 38:2-10
2 And Judah saw there a daughter of a certain Canaanite whose name was Shua; and he took her, and went in unto her.
3 And she conceived, and bore a son; and he called his name Er.
4 And she conceived again, and bore a son; and she called his name Onan.
5 And she yet again bore a son, and called his name Shelah; and he was at Chezib, when she bore him.
6 And Judah took a wife for Er his first-born, and her name was Tamar.
7 And Er, Judah's first-born, was wicked in the sight of the LORD; and the LORD slew him.
8 And Judah said unto Onan: 'Go in unto thy brother's wife, and perform the duty of a husband's brother unto her, and raise up seed to thy brother.'
9 And Onan knew that the seed would not be his; and it came to pass when he went in unto his brother's wife, that he spilled it on the ground, lest he should give seed to his brother.
10 And the thing which he did was evil in the sight of the LORD; and He slew him also.
Genesis 46:12
12 And the sons of Judah: Er, and Onan, and Shelah, and Perez, and Zerah; but Er and Onan died in the land of Canaan. And the sons of Perez were Hezron and Hamul.
Numbers 26:19
19 The sons of Judah: Er and Onan; and Er and Onan died in the land of Canaan.
1 Chronicles 9:5
5 And of the Shilonites: Asaiah the first-born and his sons.