The sons of Judah: Er, and Onan, and Shelah; which three were born to him of Shua’s daughter the Canaanitess. Er, Judah’s firstborn, was wicked in the sight of Yahweh; and he killed him.
The genealogy passes through Judah first not because he was Jacob's eldest, but because the line of David and Christ runs through him. That is why the record begins here.
AI summary
And Tamar his daughter in law bare him Pharez and Zerah,.... Through incest; they were twins, Gen 38:27 all the sons of Judah were five; who are before mentioned by name. all the sons of Judah were five; who are before mentioned by name. 1 Chronicles 2:5 ch1 2:5 ch1 2:5 ch1 2:5The sons of Pharez,.... One of the above twins, born to Judah: Hezron and Hamul; see Gen 46:12.
1Ch 2:3-5 The sons of Judah and of Pharez, 1Ch 2:3.f. - The five sons of Judah are given according to Gen 38, as the remark on Er which is quoted from Gen 38:7 of that chapter shows, while the names of the five sons are to be found also in Gen 46:12. The two sons of Pharez are according to Gen 46:12, cf. Num 26:21.
Commenting on 1 Chronicles 2:3-5