A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
isa 16:1CONTINUATION OF THE PROPHECY AS TO MOAB. (Isa 16:1-14)
lamb--advice of the prophet to the Moabites who had fled southwards to Idumea, to send to the king of Judah the tribute of lambs, which they had formerly paid to Israel, but which they had given up (Kg2 3:4-5). David probably imposed this tribute before the severance of Judah and Israel (Sa2 8:2). Therefore Moab is recommended to gain the favor and protection of Judah, by paying it to the Jewish king. Type of the need of submitting to Messiah (Psa 2:10-12; Rom 12:1).
from Sela to--rather, "from Petra through (literally, 'towards') the wilderness" [MAURER]. "Sela" means "a rock," Petra in Greek; the capital of Idumea and Arabia-PetrÃ&brvbr;a; the dwellings are mostly hewn out of the rock. The country around was a vast common ("wilderness") or open pasturage, to which the Moabites had fled on the invasion from the west (Isa 15:7).
ruler of the land--namely, of Idumea, that is, the king of Judah; Amaziah had become master of Idumea and Sela (Kg2 14:7).
isa 16:2cast out of . . . nest--rather, "as a brood cast out" (in apposition with "a wandering bird," or rather, wandering birds), namely, a brood just fledged and expelled from the nest in which they were hatched [HORSLEY]. Compare Isa 10:14; Deu 32:11.
daughters of Moab--that is, the inhabitants of Moab. So Kg2 19:21; Psa 48:11; Jer 46:11; Lam 4:22 [MAURER].
at the fords--trying to cross the boundary river of Moab, in order to escape out of the land. EWALD and MAURER make "fords" a poetical expression for "the dwellers on Arnon," answering to the parallel clause of the same sense, "daughters of Moab."
isa 16:3GESENIUS, MAURER, &c., regard these verses as an address of the fugitive Moabites to the Jews for protection; they translate Isa 16:4, "Let mine outcasts of Moab dwell with thee, Judah"; the protection will be refused by the Jews, for the pride of Moab (Isa 16:6). VITRINGA makes it an additional advice to Moab, besides paying tribute. Give shelter to the Jewish outcasts who take refuge in thy land (Isa 16:3-4); so "mercy" will be shown thee in turn by whatever king sits on the "throne" of "David" (Isa 16:5). Isaiah foresees that Moab will be too proud to pay the tribute, or conciliate Judah by sheltering its outcasts (Isa 16:6); therefore judgment shall be executed. However, as Moab just before is represented as itself an outcast in Idumea, it seems incongruous that it should be called on to shelter Jewish outcasts. So that it seems rather to foretell the ruined state of Moab when its people should beg the Jews for shelter, but be refused for their pride.
make . . . shadow as . . . night . . . in . . . noonday--emblem of a thick shelter from the glaring noonday heat (Isa 4:6; Isa 25:4; Isa 32:2).
bewray . . . wandereth--Betray not the fugitive to his pursuer.
isa 16:4Rather, "Let the outcasts of Moab dwell with thee" (Judah) [HORSLEY].
for the extortioner, &c.--The Assyrian oppressor probably.
is at an end--By the time that Moab begs Judah for shelter, Judah shall be in a condition to afford it, for the Assyrian oppressor shall have been "consumed out of the land."
isa 16:5If Judah shelters the suppliant Moab, allowing him to remain in Idumea, a blessing will redound to Judah itself and its "throne."
truth . . . judgment . . . righteousness--language so divinely framed as to apply to "the latter days" under King Messiah, when "the Lord shall bring again the captivity of Moab" (Psa 72:2; Psa 96:13; Psa 98:9; Jer 48:47; Rom 11:12).
hasting--"prompt in executing."
isa 16:6We--Jews. We reject Moab's supplication for his pride.
not be so--rather, "not right"; shall prove vain (Isa 25:10; Jer 48:29-30; Zep 2:8). "It shall not be so; his lies shall not so effect it."
isa 16:7Therefore--all hope of being allowed shelter by the Jews being cut off.
foundations--that is, "ruins"; because, when houses are pulled down, the "foundations" alone are left (Isa 58:12). Jeremiah, in the parallel place (Jer 48:31), renders it "men," who are the moral foundations or stay of a city.
Kirhareseth--literally, "a citadel of brick."
surely they are stricken--rather, joined with "mourn"; "Ye shall mourn utterly stricken" [MAURER and HORSLEY].
isa 16:8fields--vine-fields (Deu 32:32).
vine of Sibmah--near Heshbon: namely, languishes.
lords of . . . heathen--The heathen princes, the Assyrians, &c., who invaded Moab, destroyed his vines. So Jeremiah in the parallel place (Jer 48:32-33). MAURER thinks the following words require rather the rendering, "Its (the vine of Sibmah) shoots (the wines got from them) overpowered (by its generous flavor and potency) the lords of the nations" (Gen 49:11-12, Gen 49:22).
come . . . Jazer--They (the vine shoots) reached even to Jazer, fifteen miles from Heshbon.
wandered--They overran in wild luxuriance the wilderness of Arabia, encompassing Moab.
the sea--the Dead Sea; or else some lake near Jazer now dry; in Jer 48:32 called "the sea of Jazer"; but see on Jer 48:32 (Psa 80:8-11).
isa 16:9I--will bewail for its desolation, though I belong to another nation (see on Isa 15:5).
with . . . weeping of Jazer--as Jazer weeps.
shouting for . . . fallen--rather, "Upon thy summer fruits and upon thy luxuriant vines the shouting (the battle shout, instead of the joyous shout of the grape-gatherers, usual at the vintage) is fallen" (Isa 16:10; Jer 25:30; Jer 51:14). In the parallel passage (Jer 48:32) the words substantially express the same sense. "The spoiler is fallen upon thy summer fruits."
isa 16:10gladness--such as is felt in gathering a rich harvest. There shall be no harvest or vintage owing to the desolation; therefore no "gladness."
isa 16:11bowels--in Scripture the seat of yearning compassion. It means the inward seat of emotion, the heart, &c. (Isa 63:15; compare Isa 15:5; Jer 48:36).
sound . . . harp--as its strings vibrate when beaten with the plectrum or hand.
isa 16:12when it is seen that--rather, "When Moab shall have appeared (before his gods; compare Exo 23:15), when he is weary (that is, when he shall have fatigued himself with observing burdensome rites; Kg1 18:26, &c.), on the high place (compare Isa 15:2), and shall come to his sanctuary (of the idol Chemosh on Mount Nebo) to pray, he shall not prevail"; he shall effect nothing by his prayers [MAURER].
isa 16:13since that time--rather, "respecting that time" [HORSLEY]. BARNES translates it, "formerly" in contrast to "but now" (Isa 16:14): heretofore former prophecies (Exo 15:15; Num 21:29) have been given as to Moab, of which Isaiah has given the substance: but now a definite and steady time also is fixed.
isa 16:14three years . . . hireling--Just as a hireling has his fixed term of engagement, which neither he nor his master will allow to be added to or to be taken from, so the limit within which Moab is to fall is unalterably fixed (Isa 21:16). Fulfilled about the time when the Assyrians led Israel into captivity. The ruins of Elealeh, Heshbon, Medeba, Dibon, &c., still exist to confirm the inspiration of Scripture. The accurate particularity of specification of the places three thousand years ago, confirmed by modern research, is a strong testimony to the truth of prophecy.
Already, Tiglath-pileser had carried away the people of Damascus to Kir, in the fourth year of Ahaz (Kg2 16:9); but now in Hezekiah's reign a further overthrow is foretold (Jer 49:23; Zac 9:1). Also, Shalmaneser carried away Israel from Samaria to Assyria (Kg2 17:6; Kg2 18:10-11) in the sixth year of Hezekiah of Judah (the ninth year of Hoshea of Israel). This prophecy was, doubtless, given previously in the first years of Hezekiah when the foreign nations came into nearer collision with Judah, owing to the threatening aspect of Assyria.