Notes on the Bible, by Albert Barnes, [1834], at sacred-texts.com
A third part - This seems to have been a favorite division with the Hebrew commanders (see Jdg 7:16; Jdg 9:43; Sa1 11:11; Kg2 11:5-6) and with the Philistines also Sa1 13:17.
Succour us out of the city - David, with a reserve, would hold the city, and either support the bands in case of need, or receive them within the walls should they be compelled to flee.
Against Israel - Implying that the revolt was in a great measure that of the ten tribes, Saul's party, against the kingdom.
The wood of Ephraim - This would naturally be sought in the west of Jordan (marginal reference). But on the other hand it seems certain that the scene of this battle was on the east of Jordan. It seems therefore inevitable to conclude that some portion of the thick wood of oaks and terebinths which still runs down to the Jordan on the east side was for some reason called "the wood of Ephraim," either because it was a continuation on the east side of the great Ephraimitic forests on the west, or because of some transaction there in which Ephraim had taken part, such as the slaughter of the Midianites Jdg 7:24-25, or their own slaughter Jdg 12:6.
The battle was scattered - Probably Absalom's forces were far more numerous than David's; but, most likely by Joab's skillful generalship, the field of battle was such that numbers did not tell, and David's veteran troops were able to destroy Absalom's rabble in detail. The wood entangled them, and was perhaps full of pits, precipices, and morasses Sa2 18:17.
would seem that the two things which his vain-glory boasted in, the royal mule, and the magnificent head of hair by which he was caught in the "oak" (rather, terebinth or turpentine tree), both contributed to his untimely death.
Ten shekels - (About 25 shillings.) The word "shekel" is understood, as in Gen 20:16; Gen 37:28. See the Exo 38:24 note.
A girdle - Girdles were costly articles of Hebrew dress used to put money in Mat 10:9, and given as presents Sa1 18:4.
The man gives a remarkable incidental testimony to David's sagacity and penetration (compare Sa2 14:19), and to Joab's known unscrupulousness.
I may not tarry ... - i. e., lose time in such discourse.
Blew the trumpet - To stop the pursuit and slaughter Sa2 2:28; Sa2 20:22.
A great heap of stones - See the marginal reference. This kind of monument is common to almost all early nations.
The king's dale - Anciently the "valley" of "Shaveh" (marginal reference), and apparently in the near neighborhood of Sodom; but the exact site is not known. It quite agrees with Absalom's preference for Hebron Sa2 15:7, that his monument should be reared by him in the south. If Absalom's monument be placed in the ravine of the Kedron, the "king's dale" here is a different place from the "dale of Shaveh."
Absalom's place - literally, "Absalom's hand." (Sa1 15:12 note.)
Ahimaaz was a well-known runner Sa2 18:27. Speed was a heroic virtue in those simple times (compare Sa2 2:18). In Hezekiah's reign Ch2 30:6, Ch2 30:10 we find an establishment of running post-men; and the same name ("runners") is given Est 3:13 to the Persian posts, though at that time they rode on mules and camels.
Bear tidings - The original word is used almost exclusively of bearing good tidings, and hence, is rendered in the Septuagint (though not always) εὐαγγίζεσθαι euangelizesthai Sa2 4:10; Sa1 31:9. In Sa2 18:21, it is not "carry the good tidings," but "tell," simply "announce."
Cushi - "The Cushite," a foreign slave, perhaps of Joab's, whom he did not scruple to expose to David's anger. If, however, it is a name, it must be rendered "Haccushi." In the title to Ps. 7, "Cush, the Benjamite," cannot mean this Cushi, since the contents of the Psalm are not suitable to this occasion.
The plain - The floor of the valley through which the Jordan runs. The Cushite did not run by that road, but took the road over the hills, which may well have been the shorter but also the more difficult road. The two roads would probably meet a short distance from Mahanaim. These words, which have been thought to prove that the battle took place on the west of Jordan, are a clear proof that it took place on the east, because if the runners had had to cross the Jordan, they must both have come by the same road, which it is clear they did not.
Ahimaaz called - This marks the eager haste with which, before he had quite reached the king, he shouted out the pithy decisive word of good tidings, "Shalom!" Peace!
Hath delivered - See the margin. The figure seems to be that of confining a person within the power of his enemy, in opposition to "giving him his liberty" "in a large room," to work what mischief he pleases.
Tidings ... - Rather, "Let my lord the king receive the good tidings."
There is not in the whole of the Old Testament a passage of deeper pathos than this. Compare Luk 19:41. In the Hebrew Bible this verse commences the nineteenth chapter. The King James Version follows the Greek and Latin versions.