Ahaziah was twenty-two years old when he became king, and he reigned in Jerusalem one year. His mother’s name was Athaliah, the granddaughter of Omri.
We have here an account of the reign of Ahaziah, a short reign (of one year only), yet long enough, unless it had been better. He was called Jeho-ahaz (Ch2 21:17); here he is called Ahaz-iah, which is the same name and of the same signification, only the words of which it is compounded are transposed.
Commenting on 2 Chronicles 22:1-9
Forty two and years old was Ahaziah when he began to reign,.... In Kg2 8:26, he is said to be but twenty two years old at his accession to the throne, which is undoubtedly most correct; for this makes him to be two years older than his father when he died, who was thirty two when he began to reign, and reigned eight years, Ch2...
Forty and two years old was Ahaziah when he began to reign--(Compare Kg2 8:26). According to that passage, the commencement of his reign is dated in the twenty-second year of his age, and, according to this, in the forty-second year of the kingdom of his mother's family [LIGHTFOOT]. "If Ahaziah ascended the throne in the twenty-second year of his life, he must have been born in his father's nineteenth year.