Charles Ellicott Commentary 2 Chronicles 22:2

"Forty and two years old was Ahaziah when he began to reign; and he reigned one year in Jerusalem: and his mother`s name was Athaliah the daughter of Omri." — 2 Chronicles 22:2 (ASV)

Forty and two years old. —An error of transcription. 2 Kings 8:26 has twenty and two; and so too the Syriac and Arabic versions: the Septuagint has “twenty.” Ahaziah could not have been forty when he succeeded, because his father was only forty when he died (2 Chronicles 21:20).

Athaliah the daughter of Omri — i.e., granddaughter, as she was the daughter of Ahab and Jezebel. Kings adds, king of Israel, which the Chronicler purposely omits. (Compare to Micah 6:16: The statutes of Omri, the works of the house of Ahab.)