John Gill Bible Commentary

I will praise thee, O Lord my God, with all my heart,.... And under that consideration, that he was his God, and which itself is sufficient matter of praise; this makes him amiable, and such he is, love itself: this is a blessing of pure grace, and is the foundation of all other blessings, and continues for ever: this work of praise, which is no other than ascribing glory to God, and giving thanks unto him for mercies received, the psalmist determines to do with his whole heart, which is to be engaged in every spiritual service; even all of it, all that is within it, every power and faculty of the soul, Psa 103:1, which is expressive not of perfection, but sincerity: and I will glorify thy name for evermore; by celebrating the perfections of his nature, by giving him the glory of the works of his hands, by praising him for all favours, by devoting himself unto him, and by doing all things for his glory, and that for ever, in time as long as he lived, and to all eternity.