Rejoice in Jehovah, ye righteous. Here the inspired writer addresses believers or the righteous by name, because they alone are capable of proclaiming the glory of God. Unbelievers, who have never tasted his goodness, cannot praise him from the heart, and God has no pleasure in his name being pronounced by their unholy tongues. But the context shows more distinctly why this exhortation is suitable for believers only. Many, accordingly, expound the latter clause, Praise is comely for the upright, as meaning, that if the ungodly or hypocrites attempt this exercise, it will turn to the reproach and dishonor of God rather than to his praise; nay, more, that they only profane his holy name. It is, no doubt, very true, as I have already remarked, that God creates for himself a church in the world by gracious adoption, for the express purpose, that his name may be duly praised by witnesses suitable for such a work. But the real meaning of the clause, Praise is comely for the upright, is, that there is no exercise in which they can be better employed. And, assuredly, since God by his daily benefits furnishes them with such matter for celebrating his glory, and since his boundless goodness, as we have elsewhere seen, is laid up as a peculiar treasure for them, it were disgraceful and utterly unreasonable for them to be silent in the praises of God. The amount of the matter is, that the principal exercise in which it becomes the righteous to be employed is to publish among men the righteousness, goodness, and power of God, the knowledge of which is implanted in their minds. Following other interpreters, I have translated the clause, Praise is comely, but the word rendered comely may also be properly rendered desirable, if we view it as derived from the Hebrew word 'vh, avah, which signifies to wish or desire. And certainly, when God allures believers so sweetly, it is proper that they employ themselves in celebrating his praises with their whole hearts. It is also to be observed, that when the prophet, after having in the first clause used the appellation, the righteous, immediately adds the words, the upright, which comprehend the inward integrity of the heart, he defines what true righteousness is, or in what it consists.

Rejoice in the Lord, O ye righteous - This is the sentiment with which the preceding psalm closes. See the notes at Psalm 32:11.
For praise is comely for the upright - Is befitting, suitable, proper. That is, the upright - the righteous - have abundant cause for praise, and it is for them a suitable employment, or one which becomes them. A man who is upright, or who is a righteous man, has in this very fact much which lays a foundation for praise, for the fact that he has such a character is to be traced to the grace of God, and this in itself is a more valuable possession than gold or kingly crowns would he. That he is not an open violator of the law of God; that he is not intemperate; that he is not the victim of raging lusts and passions; that he is not a dishonest man; that he is not profane; that he is not an infidel or a scoffer; that he is a pious man - a redeemed man - a man of good character - an heir of heaven - is the highest blessing that could be conferred on him; and he who has been saved from outbreaking transgression and crime in a world like this, and has been enabled to live an upright life, has eminently occasion to praise and bless God. Assuredly for such a man praise is an appropriate employment, for such a man it is "comely."

Rejoice in the Lord - It is very likely that the last verse of the preceding Psalm was formerly the first verse of this. As this Psalm has no title, the verse was the more easily separated. In the preceding Psalm we have an account of the happiness of the justified man: in this, such are taught how to glorify God, and to praise him for the great things he had done for them.
Praise is comely for the upright - It is right they should give thanks to Him, who is the fountain whence they have received all the good they possess and thankfulness becomes the lips of the upright.

Rejoice in the LORD, O ye righteous: [for] praise is (a) comely for the upright.
(a) It is the duty of the godly to set forth the praises of God for his mercy and power showed to them.

Rejoice in the Lord, O ye righteous,.... See Gill on Psalm 32:11;
for praise is comely for the upright; it becomes them; it is their duty; they are bound unto it by the mercies and favours they have received; should they not give praise to God, the stones of the wall would cry out, and rebuke them for their ingratitude: it is beautiful, and looks lovely in them; it is an ornament to them, and is, in the sight of God, of great esteem: it is very acceptable to him, and when grace is in exercise, and their hearts in tune, being sensibly touched and impressed with the goodness of God, it is desirable by them, and is pleasant and delightful to them.

Holy joy is the heart and soul of praise, and that is here pressed upon the righteous. Thankful praise is the breath and language of holy joy. Religious songs are proper expressions of thankful praise. Every endowment we possess, should be employed with all our skill and earnestness in God's service. His promises are all wise and good. His word is right, and therefore we are only in the right when we agree with it. His works are all done in truth. He is the righteous Lord, therefore loveth righteousness. What a pity it is that this earth, which is so full of the proofs and instances of God's goodness, should be so empty of his praises; and that of the multitudes who live upon his bounty, there are so few who live to his glory! What the Lord does, he does to purpose; it stands fast. He overrules all the counsels of men, and makes them serve his counsels; even that is fulfilled, which to us is most surprising, the eternal counsel of God, nor can any thing prevent its coming to pass.

A call to lively and joyous praise to God for His glorious attributes and works, as displayed in creation, and His general and special providence, in view of which, the Psalmist, for all the pious, professes trust and joy and invokes God's mercy. (Psalm. 33:1-22)
The sentiment falls in with Psalm 32:11 (compare 1-Corinthians 14:15). The instruments (Psalm 92:3; Psalm 144:9) do not exclude the voice.

The call contained in this hexastich is addressed to the righteous and upright, who earnestly seek to live a godly and God-pleasing life, and the sole determining rule of whose conduct is the will and good pleasure of God. These alone know God, whose true nature finds in them a clear mirror; so on their part they are joyfully to confess what they possess in Him. For it is their duty, and at the same time their honour, to praise him, and make their boast in Him. נאוה is the feminine of the adjective נאוה (formed out of נאוי), as in Psalm 147:1, cf. Proverbs 19:10. On כּנּור (lxx κιθάρα, κινύρα) and נבל (lxx ψαλτήριον, νάβλα, ναῦλα, etc.) vid., Introduction @a7II. נבל is the name given to the harp or lyre on account of its resemblance to a skin bottle or flash (root נב, to swell, to be distended), and נבל עשׂור, "harp of the decade,"' is the ten-stringed harp, which is also called absolutely עשׂור, and distinguished from the customary נבל, in Psalm 92:4. By a comparison of the asyndeton expressions in Psalm 35:14, Jeremiah 11:19, Aben-Ezra understands by נבל עשור two instruments, contrary to the tenour of the words. Gecatilia, whom he controverts, is only so far in error as that he refers the ten to holes (נקבים) instead of to strings. The בּ is Beth instrum., just like the expression κιθαρίζειν ἐν κιθάραις, Revelation 14:2. A "new song" is one which, in consequence of some new mighty deeds of God, comes from a new impulse of gratitude in the heart, Psalm 40:4, and frequently in the Psalm, Isaiah 42:10, Judith 6:13, Revelation 5:9. In היטיבוּ the notions of scite and strenue, suaviter and naviter, blend. With בּתרוּעה, referring back to רננו, the call to praise forms, as it were, a circle as it closes.