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 ) .