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
luk 21:1THE WIDOW'S TWO MITES. (Luk 21:1-4)
looked up--He had "sat down over against the treasury" (Mar 12:41), probably to rest, for He had continued long standing as he taught in the temple court (Mar 11:27), and "looking up He saw"--as in Zaccheus' case, not quite casually.
the rich, &c.--"the people," says Mar 12:41 "cast money into the treasury, and many rich east in much"; that is, into chests deposited in one of the courts of the temple to receive the offerings of the people towards its maintenance (Kg2 12:9; Joh 8:20).
luk 21:2two mites--"which make a farthing" (Mar 12:42), the smallest Jewish coin. "She might have kept one" [BENGEL].
luk 21:3And he said--"to His disciples," whom He "called to Him" (Mar 12:43), to teach from it a great future lesson.
more than . . . all--in proportion to her means, which is God's standard (Co2 8:12).
luk 21:4of their abundance--their superfluity; what they had to spare," or beyond what they needed.
of her penury--or "want" (Mar 12:44) --her deficiency, of what was less than her own wants required, "all the living she had." Mark (Mar 12:44) still more emphatically, "all that she had--her whole subsistence." Note: (1) As temple offerings are needed still for the service of Christ at home and abroad, so "looking down" now, as then "up," Me "sees" who "cast in," and how much. (2) Christ's standard of commendable offering is not our superfluity, but our deficiency--not what will never be missed, but what costs us some real sacrifice, and just in proportion to the relative amount of that sacrifice. (See Co2 8:1-3.)
luk 21:5CHRIST'S PROPHECY OF THE DESTRUCTION OF JERUSALEM AND WARNINGS TO PREPARE FOR HIS SECOND COMING, SUGGESTED BY IT--HIS DAYS AND NIGHTS DURING HIS LAST WEEK. (Luke 21:5-38)
(See on Mat 24:1-3.)
luk 21:8the time--of the Kingdom, in its full glory.
go . . . not . . . after them--"I come not so very soon" (Th2 2:1-2) [STIER].
luk 21:9not terrified--(See Luk 21:19; Isa 8:11-14).
end not by and by--or immediately, not yet (Mat 24:6; Mar 13:7): that is, "Worse must come before all is over."
luk 21:10Nation, &c.--Matthew and Mark (Mat 24:8; Mar 13:8) add, "All these are the beginning of sorrows," or travail pangs, to which heavy calamities are compared (Jer 4:31, &c.).
luk 21:12brought before, &c.--The book of Acts verifies all this.
luk 21:13for a testimony--an opportunity of bearing testimony.
luk 21:18not a hair . . . perish--He had just said (Luk 21:16) they should be put to death; showing that this precious promise is far above immunity from mere bodily harm, and furnishing a key to the right interpretation of the ninety-first Psalm, and such like. Matthew adds the following (Mat 24:12): "And because iniquity shall abound, the love of many," the many or, the most--the generality of professed disciples--"shall wax cold." But he that endureth to the end shall be saved. Sad illustrations of the effect of abounding iniquity in cooling the love of faithful disciples we have in the Epistle of James, written about this period referred to, and too frequently ever since (Heb 10:38-39; Rev 2:10). "And this gospel of the kingdom shall be preached in all the world for a witness, and then shall the end come" (Mat 24:14). God never sends judgment without previous warning; and there can be no doubt that the Jews, already dispersed over most known countries, had nearly all heard the Gospel "as a witness," before the end of the Jewish state. The same principle was repeated and will repeat itself to the end.
luk 21:20by armies--encamped armies, that is, besieged: "the abomination of desolation" (meaning the Roman ensigns, as the symbols of an idolatrous, pagan, unclean power) "spoken of by Daniel the prophet" (Dan 9:27) "standing where it ought not" (Mar 13:14). "Whoso readeth [that prophecy] let him understand" (Mat 24:15).
Then . . . flee, &c.--EUSEBIUS says the Christians fled to Pella, at the north extremity of Perea, being "prophetically directed"; perhaps by some prophetic intimation still more explicit than this, which still would be their chart.
luk 21:23woe unto--"alas for."
with child, &c.--from the greater suffering it would involve; as also "flight in winter, and on the sabbath," which they were to "pray" against (Mat 24:20), the one as more trying to the body, the other to the soul. "For then shall be tribulation such as was not since the beginning of the world, nor ever shall be"--language not unusual in the Old Testament for tremendous calamities, though of this it may perhaps be literally said, "And except those days should be shortened, there should no flesh be saved, but for the elect's sake those days shall be shortened" (Mat 24:21-22). But for this merciful "shortening," brought about by a remarkable concurrence of causes, the whole nation would have perished, in which there yet remained a remnant to be afterwards gathered out. Here in Matthew and Mark (Mat 24:24; Mar 13:22) are some particulars about "false Christs," who should, "if possible"--a precious clause--"deceive the very elect." (Compare Th2 2:9-11; Rev 13:13.)
luk 21:24Jerusalem . . . trodden down . . . until, &c.--Implying (1) that one day Jerusalem shall cease to be "trodden down by the Gentiles" (Rev 11:2), as then by pagan so now by Mohammedan unbelievers; (2) that this shall be at the "completion" of "the times of the Gentiles," which from Rom 11:25 (taken from this) we conclude to mean till the Gentiles have had their full time of that place in the Church which the Jews in their time had before them--after which, the Jews being again "grafted into their own olive tree," one Church of Jew and Gentile together shall fill the earth (Rom. 11:1-36). What a vista this opens up!
luk 21:25signs, &c.--Though the grandeur of this language carries the mind over the head of all periods but that of Christ's second coming, nearly every expression will be found used of the Lord's coming in terrible national judgments, as of Babylon, &c.; and from Luk 21:28, Luk 21:32, it seems undeniable that its immediate reference was to the destruction of Jerusalem, though its ultimate reference beyond doubt is to Christ's final coming.
luk 21:28redemption--from the oppression of ecclesiastical despotism and legal bondage by the total subversion of the Jewish state and the firm establishment of the evangelical kingdom (Luk 21:31). But the words are of far wider and more precious import. Matthew (Mat 24:30) says, "And then shall appear the sign of the Son of man in heaven," evidently something distinct from Himself, mentioned immediately after. What this was intended to mean, interpreters are not agreed. But as before Christ came to destroy Jerusalem, some appalling portents were seen in the air, so before His personal appearing it is likely that something analogous will be witnessed, though of what nature it is vain to conjecture.
luk 21:32This generation--not "this nation," as some interpret it, which, though admissible in itself, seems very unnatural here. It is rather as in Luk 9:27.
luk 21:34surfeiting, and drunkenness--All animal excesses, quenching spirituality.
cares of this life--(See on Mar 4:7; Mar 4:19).
luk 21:36Watch . . . pray, &c.--the two great duties which in prospect of trial are constantly enjoined. These warnings, suggested by the need of preparedness for the tremendous calamities approaching, and the total wreck of the existing state of things, are the general improvement of the whole discourse, carrying the mind forward to Judgment and Vengeance of another kind and on a grander and more awful scale--not ecclesiastical or political but personal, not temporal but eternal--when all safety and blessedness will be found to lie in being able to "STAND BEFORE THE SON OF MAN" in the glory of His personal appearing.
luk 21:37in the daytime--of this His last week.
abode in the mount--that is, at Bethany (Mat 21:17).