Notes on the Bible, by Albert Barnes, [1834], at sacred-texts.com
The Moabites, who had once lorded over Israel Jdg 3:12-14, were reduced to subjection by David, and treated with extreme severity (marginal reference). In the time of Ahab they were dependent on the kingdom of Israel, to which it has been generally supposed that they fell at the separation of Israel from Judah. The Moabite monument (see Kg2 3:4), discovered in 1869, has now given reason to believe that they then recovered their independence, but were again reduced by Omri, who, with his son Ahab, is said (in round numbers) to have "oppressed" them for "forty years." Ahab's death was seized upon as an occasion for revolt, and Moab (perhaps owing to Ahaziah's sickness) easily regained her independence.
A lattice - The "upper chamber" had probably a single latticed window, through which Ahaziah fell. Windows in the East are to this day generally closed by lattices of interlaced wood, which open outward; so that, if the fastening is not properly secured, one who leans against them may easily fall out.
Baal-zebub - literally, "Lord (i. e., averter) of flies." Flies in the East constitute one of the most terrible of plages Psa 105:31; Exo 8:24; and Orientals would be as likely to have a "god of flies" as a god of storm fand thunder. To inquire Kg2 1:3 of Baal-zebub was practically to deny Yahweh. Ahaziah cast aside the last remnant of respect for the old religion, and consulted a foreign oracle, as if the voice of God were wholly silent in his own country.
For Ekron see the marginal reference.
Therefore ... - As a punishment for this insult to Yahweh.
An hairy man - Either in allusion to his shaggy cloak of untanned skin; or, more probably, an expression descriptive of the prophet's person, of his long flowing locks, abundant beard, and general profusion of hair. His costume was that of a thorough ascetic. Generally the Jews wore girdles of linen or cotton stuff, soft and comfortable. Under the girdle they wore one or two long linen gowns or shirts, and over these they had sometimes a large shawl. Elijah had only his leather girdle and his sheepskin cape or "mantle."
Then the king sent unto him - i. e., in order to seize and punish him. Compare Kg1 18:10; Kg1 22:27.
The charge of cruelty made against Elijah makes it needful to consider the question: What was Elijah's motive? And the answer is: Sharply to make a signal example, to vindicate God's honor in a striking way. Ahaziah had, as it were, challenged Yahweh to a trial of strength by sending a band of fifty to arrest one man. Elijah was not Jesus Christ, able to reconcile mercy with truth, the vindication of God's honor with the utmost tenderness for erring men, and awe them merely by His presence (compare Joh 18:6). In Elijah the spirit of the Law was embodied in its full severity. His zeal was fierce; he was not shocked by blood; he had no softness and no relenting. He did not permanently profit by the warning at Horeb (Kg1 19:12 note). He continued the uncompromising avenger of sin, the wielder of the terrors of the Lord, such exactly as he had shown himself at Carmel. He is, consequently, no pattern for Christian men Luk 9:55; but his character is the perfection of the purely legal type. No true Christian after Pentecost would have done what Elijah did. But what he did, when he did it, was not sinful. It was but executing strict, stern justice. Elijah asked that fire should fall - God made it fall; and, by so doing, both vindicated His own honor, and justified the prayer of His prophet.
The similarity of names in the two royal houses of Israel and Judah at this time, and at no other, seems to be the consequence of the close ties which united the two reigning families, and is well noted among the "undesigned coincidences" of the Old Testament. The accession of the Israelite Jehoram (Ahab's brother) took place, according to Kg2 3:1, in the eighteenth year of Jehoshaphat. Jehoram of Judah perhaps received the royal title from his father as early as his father's sixteenth year, when he was about to join Ahab against the Syrians; the same year might then be called either the eighteenth year of Jehoshaphat or the second year of Jehoram.