This Psalm is a blessed and general thanksgiving for the infinite, unspeakable, and never-failing mercies of God, both with respect to the body and the soul. In this golden and glorious Psalm, the Psalmist’s design is to embrace and set forth a summary, as it were, to all priests and ministers of the word; as a pattern for the subject matter of all sermons, exhortations, and Psalms to be delivered to the people: that all false and wicked doctrine might be avoided, and also all false worship of God; and that God might be worshipped truly with that worship required by the first commandment of the Decalogue. For this ought to be the sum and substance of all true worship,—“Let us praise the Lord, for he is good, for his mercy endureth for ever:” that is, praise, laud, and proclaim, without ceasing, the infinite largeness of his grace. Learn ye, from his word, that as he hath promised, so he is ever present with us, and continually bestows his blessings upon us; and that the riches of his goodness are boundless and inexhaustible. To fortify our hearts, therefore, against the devil, (whose whole aim and employment is to destroy in our hearts faith in God, and the knowledge of his goodness and mercy, and to cast us under doubting and sorrow,) the Psalmist repeats this holy sentence at the end of every verse—“For his mercy endureth for ever:” by which words, so often repeated, the holy man wishes to impress and fix on our hearts the doctrine of grace and the worship of the first commandment: as if he had said, it is the infinite goodness of God, and not any human works or merits of your own, that has done all these wonderful things for you. It is the pure and unspeakable greatness of God’s goodness and grace, that pours forth all these things upon you, and therefore they are poured forth upon you freely and without any merit or deserving of yours, and even while you are wholly undeserving of such mercies. In this repeated expression also the Psalmist refers, after the manner of the prophets, to the promise of Christ to come; for it was from no works of men, nor from any merit of theirs, that the promise of Christ was given unto Abraham, which said, “In thy seed shall all the nations of the earth be blessed.”