Divrey Hayamim Alef 2:3

3 The Bnei Yehudah: Er, and Onan, and Shelah, which three were born unto him of Bat-Shua the Kanaanit. And Er, the bechor of Yehudah, was rah in the eyes of Hashem; and He put him to death.

Divrey Hayamim Alef 2:3 Meaning and Commentary

1 Chronicles 2:3

The sons of Judah
The genealogy begins with him, though the fourth son of Jacob; because, as Kimchi says, this book treats chiefly of the kings of Judah; but rather not only because Jesse and David sprang from him, but also the King Messiah:

Er, and Onan, and Shelah, which three were born unto him of the
daughter of Shua the Canaanitess;
see ( Genesis 38:2 Genesis 38:12 ) ,

and Er, the firstborn of Judah, was evil in the sight of the Lord;
because he did that which was evil:

and he slew him;
he died by the immediate hand of God, and so his brother Onan, being wicked also, ( Genesis 38:7 Genesis 38:10 ) .

Divrey Hayamim Alef 2:3 In-Context

1 These are the Bnei Yisroel: Reuven, Shim’on, Levi, and Yehudah, Yissakhar, and Zevulun,

2 Dan, Yosef, and Binyamin, Naphtali, Gad, and Asher.

3 The Bnei Yehudah: Er, and Onan, and Shelah, which three were born unto him of Bat-Shua the Kanaanit. And Er, the bechor of Yehudah, was rah in the eyes of Hashem; and He put him to death.

4 And Tamar his kallah (daughter-in-law) bore him Peretz and Zerach. All the Bnei Yehudah were five.

5 The Bnei Peretz: Chetzron, and Chamul.