Sing to Jehovah a new song. This exordium proves what I have just said, that the exhortation now given is addressed only to God's people; for the singular goodness which is particularly extended to them affords more ample matter of praise. The probable conjecture is, that the Psalm was composed at the time when the people were begun to rejoice, or after they had returned to their native country from the Babylonish captivity. We will see from the context that a promise is given of recovery from their ruined condition. The object, I think, of the Psalmist, is to encourage them to expect the full and complete deliverance, some prelude of which had been suddenly and unexpectedly given in the permission to return. As the Church was not fully restored at once, but was with difficulty and only after a long period brought to a state of vigor, comfort such as this was much needed. The Spirit of God would also furnish a remedy for evils which were afterwards to break out; for the Church had scarcely begun to respire when it was again harassed with various evils, and oppressed by the cruel tyranny of Antiochus, which was followed up by a dreadful dispersion. The Psalmist had good reason therefore for animating the godly to look forward for the full accomplishment of the mercy of God, that they might be persuaded of divine protection until such time as the Messiah should arise who would gather all Israel. He calls this a new song, as we have noticed elsewhere, to distinguish it from those with which the saints commonly and daily praised God, for praise is their continued exercise. It follows that he speaks of some rare and unusual benefit, demanding signal and particular thanksgiving. And I am disposed to think that whoever may have been the author of the Psalm, he alludes to that passage in Isaiah, (Isaiah 42:10,) "Sing unto the Lord a new song," when he speaks of the future restoration of the Church, and the eternal kingdom of Christ. In the second clause of the verse there is a promise implied. For though he proceeds to exhort the Lord's people to sing God's praises together, he hints along with this that the Church would coalesce again into one body, so as to celebrate God's praises in the solemn assembly. We know that so scattered were the Israelites, that the sacred songs ceased to be sung, as elsewhere they complain of being called upon to sing -- "How shall we sing the songs of the Lord in a strange land?" (Psalm 137:4.) He bids them prepare therefore after this sad dispersion for holding their sacred assemblies again.

Praise ye the Lord - Margin, Hallelujah. See the notes at Psalm 146:1.
Sing unto the Lord a new song - As if there was a new and a special occasion for praise. This would be so if the psalm was composed on the return from the exile; on the rebuilding of the city; and on the re-dedication of the temple. On the meaning of the language, see Psalm 33:3, note; Revelation 5:9, note; Revelation 14:3, note; see also Psalm 96:1; Isaiah 42:10.
And his praise in the congregation of saints - In the assembly of the people of God. See Psalm 148:14, note; Psalm 111:1, note.

Sing unto the Lord a new song - That is, as we have often had occasion to remark, an excellent song, the best we can possibly pronounce. So the word חדש chadash is often understood; and so the word novus, "new," was often used among the Latin writers: -
Pollio amat nostram, quamvis sit rustica, musam.
Pollio et ipse facit.
Nova Carmina Virg. Ecl. iii., ver. 84.
Pollio loves my lines, although rude:
Pollio himself makes excellent odes.
Tamely and inexpressively translated by Dryden: -
"Pollio my rural verse vouchsafes to read.
My Pollio writes himself."
O what a falling off is here!
Servius, in his comment on nova, says, magna, Miranda. Nova means great, admirable.
So on novum nectar, Ecl. v., ver. 71, he says, id est, magna dulcedo; "nectar of Excellent flavor."
Congregation of saints - The Israelites, who were, by profession and by injunction, a holy people.

Praise ye the LORD. Sing unto the LORD (a) a new song, [and] his praise in the congregation of saints.
(a) For his rare and manifold benefits bestowed on his Church.

Praise ye the Lord,.... Or "hallelujah"; the title of the psalm, according to many;
sing unto the Lord a new song; for a new mercy received, a new victory obtained, or a new salvation wrought; more particularly the new song of redeeming grace through Jesus Christ, the song of the Lamb, in distinction from the old song of Moses and the children of Israel at the Red sea, on account of their deliverance, which was typical of salvation by Christ, the oldest, being the first song we read of; but this is a new one, which none but the redeemed of the Lamb can sing; a song suited to Gospel times, in which all things are new, a new church state, new ordinances, a new covenant, and a new and living way to the holiest of all; a song proper for renewed persons to sing, who have new favours continually to bless and praise the Lord for;
and his praise in the congregation of saints: such who are partakers of the blessings of divine goodness; are separated and distinguished from others by the grace of God; are sanctified and brought into a Gospel church state; and who gather and assemble together to worship God, and attend upon him in his word and ordinances, and in such assemblies the praises of God are to be sung; which being done socially, the saints are assisting to one another in this service; and it is done with greater solemnity, and is more to the public honour and glory of God; thus Gospel churches are called upon to sing the praises of God among themselves, Ephesians 5:19; and have Christ for an example going before them, Psalm 22:22.

New mercies continually demand new songs of praise, upon earth and in heaven. And the children of Zion have not only to bless the God who made them, but to rejoice in him, as having created them in Christ Jesus unto good works, and formed them saints as well as men. The Lord takes pleasure in his people; they should rejoice in Him. When the Lord has made sinners feel their wants and unworthiness, he will adorn them with the graces of his Spirit, and cause them to bear his image, and rejoice in his happiness for ever. Let his saints employ their waking hours upon their beds in songs of praise. Let them rejoice, even upon the bed of death, assured that they are going to eternal rest and glory.

This Psalm sustains a close connection with the foregoing. The chosen people are exhorted to praise God, in view of past favors, and also future victories over enemies, of which they are impliedly assured. (Psalm 149:1-9)
(Compare Psalm 96:1).

A period, in which the church is renewing its youth and drawing nearer to the form it is finally to assume, also of inward necessity puts forth new songs. Such a new era has now dawned for the church of the saints, the Israel that has remained faithful to its God and the faith of its fathers. The Creator of Israel (עשׂיו, plural, with the plural suffix, like עשׂי in Job 35:10, עשׂיך in Isaiah 54:5, cf. עשׂו in Job 40:19; according to Hupfeld and Hitzig, cf. Ew. 256, b, Ges. 93, 9, singular; but aj, ajich, aw, are always really plural suffixes) has shown that He is also Israel's Preserver and the King of Zion, that He cannot leave the children of Zion for any length of time under foreign dominion, and has heard the sighing of the exiles (Isaiah 63:19; Isaiah 26:13). Therefore the church newly appropriated by its God and King is to celebrate Him, whose Name shines forth anew out of its history, with festive dance, timbrel, and cithern. For (as the occasion, hitherto only hinted at, is now expressly stated) Jahve takes a pleasure in His people; His wrath in comparison with His mercy is only like a swiftly passing moment (Isaiah 54:7.). The futures that follow state that which is going on at the present time. ענוים is, as frequently, a designation of the ecclesia pressa, which has hitherto, amidst patient endurance of suffering, waited for God's own act of redemption. He now adorns them with ישׁוּעה, help against the victory over the hostile world; now the saints, hitherto enslaved and contemned, exult בכבוד, in honour, or on account of the honour which vindicates them before the world and is anew bestowed upon them (בּ of the reason, or, which is more probable in connection with the boldness of the expression, of the state and mood);
(Note: Such, too (with pomp, not "with an army"), is the meaning of μετὰ δόξης in 1 Macc. 10:60; 14:4, 5, vid., Grimm in loc.))
they shout for joy upon their beds, upon which they have hitherto poured forth their complaints over the present (cf. Hosea 7:14), and ardently longed for a better future (Isaiah 26:8); for the bed is the place of soliloquy (Psalm 4:5), and the tears shed there (Psalm 6:7) are turned into shouts of joy in the case of Israel.