Ochozias was two and twenty years old when he began to reign, and he reigned one year in Jerusalem: the name of his mother was Athalia the daughter of Amri king of Israel.

a son of twenty and two years is Ahaziah in his reigning, and one year he hath reigned in Jerusalem, and the name of his mother is Athaliah daughter of Omri king of Israel,

Ahaziah was twenty-two years old when he became king, and he was ruling in Jerusalem for one year. His mother's name was Athaliah, the daughter of Omri, king of Israel.

Ahaziah was twenty-two years old when he had begun to reign, and he reigned for one year in Jerusalem. The name of his mother was Athaliah, the daughter of Omri, the king of Israel.

Such names as Athaliah, Jehoram, and Ahaziah, indicate that the Baal-worshipping kings of Israel did not openly renounce the service of Yahweh. Athaliah is "the time for Yahweh;" Ahaziah "the possession of Yahweh;" Jehoram, or Joram, "exalted by Yahweh."
The daughter of Omri - "Son" and "daughter" were used by the Jews of any descendants (compare Matthew 1:1). The whole race were "the children of Israel." Athaliah was the grand-daughter of Omri (see the margin). Her being called "the daughter of Omri" implies that an idea of special greatness was regarded as attaching to him, so that his name prevailed over that of Ahab. Indications of this ideal greatness are found in the Assyrian inscriptions, where the early name for Samaria is Beth-Omri, and where even Jehu has the title of "the son of Omri."

Two and twenty years old was Ahaziah when he began to reign - In 2-Chronicles 22:2, it is said, forty and two years old was Ahaziah when he began to reign; this is a heavy difficulty, to remove which several expedients have been used. It is most evident that, if we follow the reading in Chronicles, it makes the son two years older than his own father! for his father began to reign when he was thirty-two years old, and reigned eight years, and so died, being forty years old; see 2-Kings 8:17. Dr. Lightfoot says, "The original meaneth thus: Ahaziah was the son of two and forty years; namely, of the house of Omri, of whose seed he was by the mother's side; and he walked in the ways of that house, and came to ruin at the same time with it. This the text directs us to look after, when it calleth his mother the daughter of Omri, who was indeed the daughter of Ahab. Now, these forty-two years are easily reckoned by any that will count back in the Chronicle to the second of Omri. Such another reckoning there is about Jechoniah, or Jehoiachin, 2-Kings 24:8 : Jehoiachin was eighteen years old when he began to reign. But, 2-Chronicles 36:9, Jehoiachin was the son of the eight years; that is, the beginning of his reign fell in the eighth year of Nebuchadnezzar, and of Judah's first captivity." - Works, vol. i., p. 87.
After all, here is a most manifest contradiction, that cannot be removed but by having recourse to violent modes of solution. I am satisfied the reading in 2-Chronicles 22:2 (note), is a mistake; and that we should read there, as here, twenty-two instead of forty-two years; see the note there. And may we not say with Calmet, Which is most dangerous, to acknowledge that transcribers have made some mistakes in copying the sacred books, or to acknowledge that there are contradictions in them, and then to have recourse to solutions that can yield no satisfaction to any unprejudiced mind? I add, that no mode of solution yet found out has succeeded in removing the difficulty; and of all the MSS. which have been collated, and they amount to several hundred, not one confirms the reading of twenty-two years. And to it all the ancient versions are equally unfriendly.

(o) Two and twenty 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 king of Israel.
(o) Which is to be understood, that he was made king when his father reigned, but after his father's death he was confirmed king when he was forty-two years old, as in (2-Chronicles 22:2).

Two and twenty years old was Ahaziah when he began to reign,.... In 2-Chronicles 22:2 he is said to be forty two years of age; for the solution of that difficulty See Gill on 2-Chronicles 22:2,
and he reigned one year in Jerusalem; which was the whole of his reign:
and his mother's name was Athaliah the daughter of Omri king of Israel; that is, his granddaughter; for she was the daughter of Ahab the son of Omri, 2-Kings 8:18, it was usual for grandchildren to be called children, sons and daughters, and perhaps she might be educated in the family of Omri.