Jehoahaz - The writer of Chronicles calls him indifferently Jeboahaz and Abaziah, which are equivalent names (2 Kings 8:24 note).

Save Jehoahaz the youngest - This person had at least three names, Jehoahaz, Ahaziah, (2 Chronicles 22:1), and Azariah, (2 Chronicles 22:6).

And they came up into Judah, and brake into it, &c. l In an hostile manner:

and carried away all the substance that was found in the king's house, his gold, silver, and precious things, the rich furniture of his palace; no mention is made of any other plunder in the city, or the country; so that they seem to have had their principal eye to the king's palace, and the spoil of that; being so directed by the providence of God, who had stirred them up to do this as a punishment of Jehoram:

and his sons also, and his wives; these they also carried away, all but Athaliah, who hid herself; he through his disease not being able to make any opposition, or to get any forces together to withstand them:

so that there was never a son left him, save Jehoahaz, the youngest of his sons; the same that is called Ahaziah and Azariah, 2 Chronicles 22:1 so the prophecy in 2 Chronicles 21:14 was fulfilled.

And they came up into Judah, and brake into it, and carried away all the substance that was found in the king's house, and his sons also, and his wives; so that there was never a son left him, save {k} Jehoahaz, the youngest of his sons.

(k) Called also Ahaziah, as in 2Ch 22:1 or Azariah in 2Ch 22:6.

21:17 His wives - Whom also they slew, chap.22:1, except Ahaziah and Athaliah; who possibly were hidden in some secret place. Left him - Blood for blood. He had slain all his brethren; they slay all his sons, but one. And he had not escaped, had be not been of the house of David; which must not be extirpated, like that of Ahab: because a blessing was in it; no less a blessing than that of the Messiah.

carried...: Heb. carried captive

Jehoahaz: also called, Ahaziah, or, Azariah

Margin Jehoahaz

Called Ahaziah, 2Chr 22:1,6 and Azariah:

21:12-20 A warning from God was sent to Jehoram. The Spirit of prophecy might direct Elijah to prepare this writing in the foresight of Jehoram's crimes. He is plainly told that his sin should certainly ruin him. But no marvel that sinners are not frightened from sin, and to repentance, by the threatenings of misery in another world, when the certainty of misery in this world, the sinking of their estates, and the ruin of their health, will not restrain them from vicious courses. See Jehoram here stripped of all his comforts. Thus God plainly showed that the controversy was with him, and his house. He had slain all his brethren to strengthen himself; now, all his sons are slain but one. David's house must not be wholly destroyed, like those of Israel's kings, because a blessing was in it; that of the Messiah. Good men may be afflicted with diseases; but to them they are fatherly chastisements, and by the support of Divine consolations the soul may dwell at ease, even when the body lies in pain. To be sick and poor, sick and solitary, but especially to be sick and in sin, sick and under the curse of God, sick and without grace to bear it, is a most deplorable case. Wickedness and profaneness make men despicable, even in the eyes of those who have but little religion.