Notes on the Bible, by Albert Barnes, [1834], at sacred-texts.com
Metheg-ammah must be the name of some stronghold which commanded Gath, and the taking of which made David master of Gath and her towns.
David took great numbers of the Moabites prisoners of war, and made them lie down on the ground, and then divided them by a measuring line into three parts, putting two-thirds to death, and saving alive one-third. The cause of the war with the Moabites, who had been very friendly with David Sa1 22:3-4, and of this severe treatment, is not known. But it seems likely, from the tone of Psa 60:1-12 that David had met with some temporary reverse in his Syrian wars, and that the Moabites and Edomites had treacherously taken advantage of it, and perhaps tried to cut off his retreat.
Hadadezer - Not (see the margin) Hadarezer. Hadadezer, is the true form, as seen in the names Benhadad, Hadad (Kg1 15:18, etc.; Kg1 11:14, etc.). Hadad was the chief idol, or sun-god, of the Syrians.
To recover his border - literally, to cause his hand to return. The phrase is used sometimes literally, as e. g. Exo 4:7; Kg1 13:4; Pro 19:24; and sometimes figuratively, as Isa 1:25; Isa 14:27; Amo 1:8; Psa 74:11. The exact force of the metaphor must in each case be decided by the context. If, as is most probable, this verse relates to the circumstances more fully detailed in Sa2 10:15-19, the meaning of the phrase here will be when he (Hadadezer) went to renew his attack (upon Israel), or to recruit his strength against Israel, at the river Euphrates.
Seven hundred horsemen - It should be seven thousand, as in Ch1 18:4.
Syrians of Damascus - The Syrians (Aram), whose capital was Damascus, were the best known and most powerful. Damascus (written Darmesek in marginal references, according to the late Aramean orthography) is first mentioned in Gen 15:2. According to Nicolaus of Damascus, cited by Josephus, the Syrian king's name was Hadad.
Garrisons - The word is used for officers in Kg1 4:5, Kg1 4:19, and some think that that is its meaning here. Perhaps, however, it is best to take it with the King James Version in the same sense as in Sa1 10:5; Sa1 13:3.
Brought gifts - Rather, "tribute" (and in Sa2 8:2); meaning they became subject and tributary.
Betah and Berothai - These names (see also margin) have not been identified with certainty.
Exceeding much brass - "Wherewith Solomon made the brazen sea, and the pillars, and the vessels of brass" Ch1 18:8. The Septuagint and Vulgate both add these words here, so that perhaps they have fallen out of the Hebrew text. For the existence of metals in Lebanon or Antilebanon, see Deu 8:9.
Hamath - This appears as an independent kingdom so late as the time of Senacherib Isa 37:13. But in the time of Nebuchadnezzar, both Hamath and Arpad appear to have been incorporated in the kingdom of Damascus Jer 49:23.
Joram - Or, more probably, Hadoram. See the margin.
Syria - Rather, as in Ch1 18:11, Edom, which is manifestly the right reading, both because Edom, Moab, and Ammon are so frequently joined together, and because David's Syrian spoil is expressly mentioned at the end of the verse. (The Hebrew letters for Aram (Syria) and Edom are very similar.)
The Syrians - Read the Edomites, as in marginal references (compare Psa 60:1-12 title), and as the context Sa2 8:14 requires. For a further account of this war of extermination with Edom, see Kg1 11:15-16. The war with Edom was of some duration, not without serious reverses and dangers to the Israelites (Sa2 8:2 note). The different accounts probably relate to different parts of the campaign.
For a similar account of the officers of Solomon's kingdom, see Kg1 4:1-6, where Jehoshaphat is still the recorder, and Benaiah is advanced to be captain of the host in the room of Joab. The recorder seems to have been a high officer of state, a kind of chancellor, whose office was to keep a record of the events of the kingdom for the king's information, and hence, he would naturally be the king's adviser. See Est 6:1-2; Isa 36:22; Ch2 34:8. Such an officer is found among the ancient Egyptians and Persians.
Ahimelech the son of Abiathar - According to Sa1 22:9-23, Abiathar, Zadok's colleague, was the son of Ahimelech. Abiathar the son of Ahimelech continued to be priest through the reign of David. (Compare also Kg1 1:7, Kg1 1:42; Kg1 2:22-27.) It almost necessarily follows that there is some error in the text.
The scribe - Or secretary of state Kg2 12:10; Kg2 18:37, different from the military scribe (Jdg 5:14 note).
The Cherethites and the Pelethites - See the marginal reference note.
Chief rulers - The word כהן kôhên, here rendered a "chief ruler," is the regular word for a priest. In the early days of the monarchy the word כהן kôhên had not quite lost its etymological sense, from the root meaning to minister, or manage affairs, though in later times its technical sense alone survived.