Readers of Matthew Henry's commentary on the Psalms will note that he commonly provides exhortations on how to rightly sing each Psalm. I have collected his comments in this regard on the first eight psalms as an encouragement to note these exhortations when reading his commentary.
Psalm 1.4-6:In singing these verses, being duly affected with the malignant and dangerous nature of sin, the transcendent excellencies of the divine law, and the power and efficacy of God's grace, from which our fruit is found, we must teach and admonish ourselves, and one another, to watch against sin and all approaches towards it, to converse much with the word of God, and abound in the fruit of righteousness; and, in praying over them, we must seek to God for his grace both to fortify us against every evil word and work and to furnish us for every good word and work.
Psalm 2.1-9:In singing these verses, and praying over them, let us possess ourselves with a holy dread of the wicked man's portion, and deprecate it with a firm and lively expectation of the judgment to come, and stir up ourselves to prepare for it, and with a holy care to approve ourselves to God in every thing, entreating his favour with our whole hearts.
Psalm 2.10-12:In singing this, and praying it over, we must give glory to Christ as the eternal Son of God and our rightful Lord, and must take comfort from this promise, and plead it with God, that the kingdom of Christ shall be enlarged and established and shall triumph over all opposition.
Psalm 3.1-3:In singing this, and praying it over, we should have our hearts filled with a holy awe of God, but at the same time borne up with a cheerful confidence in Christ, in whose mediation we may comfort and encourage ourselves and one another. We are the circumcision, that rejoice in Christ Jesus.
Psalm 3.4-8:In singing this, and praying it over, we should possess ourselves with an apprehension of the danger we are in from the multitude and malice of our spiritual enemies, who seek the ruin of our souls by driving us from our God, and we should concern ourselves in the distresses and dangers of the church of God, which is every where spoken again, every where fought against; but, in reference to both, we should encourage ourselves in our God, who owns and protects and will in due time crown his own interest both in the world and in the hearts of his people.
Psalm 4.1-5:In singing this, and praying it over, we must own the satisfaction we have had in depending upon God and committing ourselves to him, and encourage ourselves, and one another to continue still hoping and quietly waiting for the salvation of the Lord.
Psalm 4.6-8:In singing these verses we must preach to ourselves the doctrine of the provoking nature of sin, the lying vanity of the world, and the unspeakable happiness of God's people; and we must press upon ourselves the duties of fearing God, conversing with our own hearts, and offering spiritual sacrifices; and in praying over these verses we must beg of God grace thus to think and thus to do.
Psalm 5.1-6:In singing these verses, and praying over them, let us, with a holy contempt of the wealth and pleasure of this world, as insufficient to make us happy, earnestly seek the favour of God and pleasingly solace ourselves in that favour; and, with a holy indifferency about the issue of all our worldly concerns, let us commit ourselves and all our affairs to the guidance and custody of the divine Providence, and be satisfied that all shall be made to work for good to us if we keep ourselves in the love of God.
Psalm 5.7-12:In singing these verses, and praying them over, we must engage and stir up ourselves to the duty of prayer, and encourage ourselves in it, because we shall not seek the Lord in vain; and must express our detestation of sin, and our awful expectation of that day of Christ's appearing which will be the day of the perdition of ungodly men.
Psalm 6.1-7:In singing these verses, and praying them over, we must by faith put ourselves under God's guidance and care, and then please ourselves with his mercy and grace and with the prospect of God's triumphs at last over all his enemies and his people's triumphs in him and in his salvation.
Psalm 7.1-9:In singing this, and praying over it, we must give glory to God, as a God ready to hear prayer, must own his goodness to us in hearing our prayers, and must encourage ourselves to wait upon him and to trust in him in the greatest straits and difficulties.
Psalm 7.10-17:As far as we have the testimony of an unbiased conscience for us that in any instance we are wronged and injuriously reflected on, we may, in singing these verses, lodge our appeal with the righteous God, and be assured that he will own our righteous cause, and will one day, in the last day at furthest, bring forth our integrity as the light.
Psalm 8.1-2:In singing this psalm we must do as David here does (v. 17), praise the Lord according to his righteousness, that is, give him the glory of that gracious protection under which he takes his afflicted people and of that just vengeance with which he will pursue those that afflict them. Thus we must sing to the praise of the Lord most high, who, when his enemies deal proudly, shows that he is above them.
Psalm 8.3-9:In singing this let us give God the glory of his great name, and of the great things he has done by the power of his gospel, in the chariot of which the exalted Redeemer rides forth conquering and to conquer, and ought to be attended, not only with our praises, but with our best wishes. Praise is perfected (that is, God is in the highest degree glorified) when strength is ordained out of the mouth of babes and sucklings.
In singing this and praying it over, though we must not forget to acknowledge, with suitable affections, God's common favours to mankind, particularly in the serviceableness of the inferior creatures to us, yet we must especially set ourselves to give glory to our Lord Jesus, by confessing that he is Lord, submitting to him as our Lord, and waiting till we see all things put under him and all his enemies made his footstool.