The sons of Judah; Er, and Onan, and Shelah: which three were born unto him of the daughter of Shua the Canaanitess. And Er, the firstborn of Judah, was evil in the sight of the LORD; and he slew him.
All Commentaries on 1 Chronicles 2:3 Go To 1 Chronicles 2
George Leo Haydock
Her. The crime for which he was punished is not specified in Scripture. (Calmet)
The Rabbins say that he was so enamoured of the beauty of his wife, that he treated her in the same manner as Onan did afterwards. (Cassian viii. 11.)
It is supposed that he was slain by a devil, (Calmet) like the (Tirinus) impure husbands of Sarai, Tobias vi. 14. (Haydock)