Albert Barnes Commentary 1 Kings 14:31

"And Rehoboam slept with his fathers, and was buried with his fathers in the city of David: and his mother`s name was Naamah the Ammonitess. And Abijam his son reigned in his stead." — 1 Kings 14:31 (ASV)

Slept with his fathers and was buried... (Compare to 1 Kings 11:43). This expression is a kind of formula, used for all the kings of Judah except for two or three. The writer records this fact so carefully, probably because he regards it as a continuation of God’s mercy to David.

His mother’s name... The regular mention of the queen-mother in the accounts of the kings of Judah is thought to indicate that she had an important position in the state. There are, however, only two instances where such a person seems to have exercised any power (1 Kings 15:13; 2 Kings 11:1–20).

Abijam. Abijah was probably his real name, while Abijam is a form that arose from the religious conviction of the Jews, who would not allow the divine name JAH to be part of the name of such a wicked king. Similar instances of this practice include the changing of "Bethel" to "Beth-aven" in Hosea 4:15, and perhaps "Jehoahaz" to "Ahaz" (2 Kings 15:38).