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
rev 15:1THE LAST SEVEN VIALS OF PLAGUES: SONG OF THE VICTORS OVER THE BEAST. (Rev 15:1-8)
the seven last plagues--Greek, "seven plagues which are the last."
is filled up--literally, "was finished," or "consummated": the prophetical past for the future, the future being to God as though it were past, so sure of accomplishment is His word. This verse is the summary of the vision that follows: the angels do not actually receive the vials till Rev 15:7; but here, in Rev 15:1, by anticipation they are spoken of as having them. There are no more plagues after these until the Lord's coming in judgment. The destruction of Babylon (Rev 18:2) is the last: then in Rev 19:11-16 He appears.
rev 15:2sea of glass--Answering to the molten sea or great brazen laver before the mercy seat of the earthly temple, for the purification of the priests; typifying the baptism of water and the Spirit of all who are made kings and priests unto God.
mingled with fire--answering to the baptism on earth with fire, that is, fiery trial, as well as with the Holy Ghost, which Christ's people undergo to purify them, as gold is purified of its dross in the furnace.
them that had gotten the victory over--Greek, "those (coming) off from (the conflict with) the beast-conquerors."
over the number of his name--A, B, C, Vulgate, Syriac, and Coptic omit the words in English Version, "over his mark." The mark, in fact, is the number of his name which the faithful refused to receive, and so were victorious over it.
stand on the sea of glass--ALFORD and DE BURGH explain "on (the shore of) the sea": at the sea. So the preposition, Greek, "epi," with the accusative case, is used for at, Rev 3:20. It has a pregnant sense: "standing" implies rest, Greek "epi" with the accusative case implies motion "towards." Thus the meaning is, Having come TO the sea, and now standing AT it. In Mat 14:26, where Christ walks on the sea, the Greek oldest manuscripts have the genitive, not the accusative as here. Allusion is made to the Israelites standing on the shore at the Red Sea, after having passed victoriously through it, and after the Lord had destroyed the Egyptian foe (type of Antichrist) in it. Moses and the Israelites' song of triumph (Exo 15:1) has its antitype in the saints' "song of Moses and the Lamb" (Rev 15:3). Still English Version is consistent with good Greek, and the sense will then be: As the sea typifies the troubled state out of which the beast arose, and which is to be no more in the blessed world to come (Rev 21:1), so the victorious saints stand on it, having it under their feet (as the woman had the moon, see on Rev 12:1); but it is now no longer treacherous wherein the feet sink, but solid like glass, as it was under the feet of Christ, whose triumph and power the saints now share. Firmness of footing amidst apparent instability is thus represented. They can stand, not merely as victorious Israel at the Red Sea, and as John upon the sand of the shore, but upon the sea itself, now firm, and reflecting their glory as glass, their past conflict shedding the brighter luster on their present triumph. Their happiness is heightened by the retrospect of the dangers through which they have passed. Thus this corresponds to Rev 7:14-15.
harps of God--in the hands of these heavenly virgins, infinitely surpassing the timbrels of Miriam and the Israelitesses.
rev 15:3song of Moses . . . and . . . the Lamb--The New Testament song of the Lamb (that is, the song which the Lamb shall lead, as being "the Captain of our salvation," just as Moses was leader of the Israelites, the song in which those who conquer through Him [Rom 8:37] shall join, Rev 12:11) is the antitype to the triumphant Old Testament song of Moses and the Israelites at the Red Sea (Exo. 15:1-21). The Churches of the Old and New Testament are essentially one in their conflicts and triumphs. The two appear joined in this phrase, as they are in the twenty-four elders. Similarly, Isa 12:1-6 foretells the song of the redeemed (Israel foremost) after the second antitypical exodus and deliverance at the Egyptian Sea. The passage through the Red Sea under the pillar of cloud was Israel's baptism, to which the believer's baptism in trials corresponds. The elect after their trials (especially those arising from the beast) shall be taken up before the vials of wrath be poured on the beast and his kingdom. So Noah and his family were taken out of the doomed world before the deluge; Lot was taken out of Sodom before its destruction; the Christians escaped by a special interposition of Providence to Pella before the destruction of Jerusalem. As the pillar of cloud and fire interposed between Israel and the Egyptian foe, so that Israel was safely landed on the opposite shore before the Egyptians were destroyed; so the Lord, coming with clouds and in flaming fire, shall first catch up His elect people "in the clouds to meet Him in the air," and then shall with fire destroy the enemy. The Lamb leads the song in honor of the Father amidst the great congregation. This is the "new song" mentioned in Rev 14:3. The singing victors are the 144,000 of Israel, "the first-fruits," and the general "harvest" of the Gentiles.
servant of God-- (Exo 14:31; Num 12:7; Jos 22:5). The Lamb is more: He is the SON.
Great and marvellous are thy works, &c.--part of Moses' last song (Deu 32:3-4). The vindication of the justice of God that so He may be glorified is the grand end of God's dealings. Hence His servants again and again dwell upon this in their praises (Rev 16:7; Rev 19:2; Pro 16:4; Jer 10:10; Dan 4:37). Especially at the judgment (Psa 50:1-6; Psa 145:17).
saints--There is no manuscript authority for this. A, B, Coptic, and CYPRIAN read, "of the NATIONS." C reads "of the ages," and so Vulgate and Syriac. The point at issue in the Lord's controversy with the earth is, whether He, or Satan's minion, the beast, is "the King of the nations"; here at the eve of the judgments descending on the kingdom of the beast, the transfigured saints hail Him as "the King of the nations" (Eze 21:27).
rev 15:4Who shall not--Greek, "Who is there but must fear Thee?" Compare Moses' song, Exo 15:14-16, on the fear which God's judgments strike into the foe.
thee--so Syriac. But A, B, C, Vulgate, and CYPRIAN reject "thee."
all nations shall come--alluding to Psa 22:27-31; compare Isa 66:23; Jer 16:19. The conversion of all nations, therefore, shall be when Christ shall come, and not till then; and the first moving cause will be Christ's manifested judgments preparing all hearts for receiving Christ's mercy. He shall effect by His presence what we have in vain tried to effect in His absence. The present preaching of the Gospel is gathering out the elect remnant; meanwhile "the mystery of iniquity" is at work, and will at last come to its crisis; then shall judgment descend on the apostates at the harvest-end of this age (Greek, Mat 13:39-40) when the tares shall be cleared out of the earth, which thenceforward becomes Messiah's kingdom. The confederacy of 'the apostates against Christ becomes, when overthrown with fearful judgments, the very means in God's overruling providence of preparing the nations not joined in the Antichristian league to submit themselves to Him.
are--literally, "were": the prophetical past for the immediate future.
rev 15:5So Rev 11:19; compare Rev 16:17. "The tabernacle of the testimony" appropriately here comes to view, where God's faithfulness in avenging His people with judgments on their foes is about to be set forth. We need to get a glimpse within the Holy place to "understand" the secret spring and the end of God's righteous dealings.
behold--omitted by A, B, C, Syriac, and ANDREAS. It is supported only by Vulgate, Coptic, and PRIMASIUS, but no manuscript.
rev 15:6having--So B reads. But A and C, read "who have": not that they had them yet (compare Rev 15:7), but they are by anticipation described according to their office.
linen--So B reads. But A, C, and Vulgate, "a stone." On the principle that the harder reading is the one least likely to be an interpolation, we should read, "a stone pure ('and' is omitted in A, B, C, and ANDREAS), brilliant" (so the Greek): probably the diamond. With English Version, compare Act 1:10; Act 10:30.
golden girdles--resembling the Lord in this respect (Rev 1:13).
rev 15:7one of the four beasts--Greek, "living creatures." The presentation of the vials to the angels by one of the living creatures implies the ministry of the Church as the medium for manifesting to angels the glories of redemption (Eph 3:10).
vials--"bowls"; a broad shallow cup or bowl. The breadth of the vials in their upper part would tend to cause their contents to pour out all at once, implying the overwhelming suddenness of the woes.
full of . . . wrath--How sweetly do the vials full of odors, that is, the incense-perfumed prayers of the saints, contrast with these!
rev 15:8temple . . . filled-- (Isa 6:4); compare Exo 40:34; Ch2 5:14, as to the earthly temple, of which this is the antitype.
the glory of God and . . . power--then fully manifested.
no man was able to enter . . . the temple--because of God's presence in His manifested glory and power during the execution of these judgments.