Genesis 21:3 - Exposition

And Abraham called the name of his son —the naming of a child by its father is, according to partitionists, a peculiarity of the Elohist as distinguished from the Jehovist, who assigns that function to the mother; but vide Genesis 16:15 — that was born unto him, whom Sarah bare to him (the latter clause being added to distinguish him from Hagar's child), Isaac— laughter; the name appointed for him by God before his birth ( Genesis 17:19 ).