Here is, 1. David's prayer for the salvation of the Lord. "Lord, thou art my Saviour; I am miserable in myself, and thou only canst make me happy; let thy salvation come to me. Hasten temporal salvation to me from my present distresses, and hasten me to the eternal salvation, by giving me the necessary qualifications for it and the comfortable pledges and foretastes of it." 2. David's dependence upon the grace and promise of God for that salvation. These are the two pillars on which our hope is built, and they will not fail us: - (1.) The grace of God: Let thy mercies come, even thy salvation. Our salvation must be attributed purely to God's mercy, and not to any merit of our own. Eternal life must be expected as the mercy of our Lord Jesus Christ, Jde 1:21. "Lord, I have by faith thy mercies in view; let me by prayer prevail to have them come to me." (2.) The promise of God: "Let it come according to thy word, thy word of promise. I trust in thy word, and therefore may expect the performance of the promise." We are not only allowed to trust in God's word, but our trusting in it is the condition of our benefit by it. 3. David's expectation of the good assurance which that grace and promise of God would give him: "So shall I have wherewith to answer him that reproaches me for my confidence in God, as if it would deceive me." When God saves those out of their troubles who trusted in him he effectually silences those who would have shamed that counsel of the poor (Psa 14:6), and their reproaches will be for ever silenced when the salvation of the saints is completed; then it will appear, beyond dispute, that it was not in vain to trust in God.

So shall I keep thy law continually,.... Which denotes not the perfection of keeping the law, but the constancy of it: the psalmist was persuaded, that so long as he had the word of truth in his mouth, and the judgments of God in his view, he should be diligent and constant in the discharge of his duty, which these directed and encouraged him unto;

for ever and ever; in this life and that to come; when the law of God will be kept, and his will done perfectly by the saints, as it now is by the angels in heaven; or this may be connected with the law of God; which law is for ever and ever, being of eternal duration and obligation. The whole may be understood of the law of faith, or doctrine of the Gospel, and be rendered, "so shall I observe thy doctrine continually"; contained in the word of truth; which doctrine is for ever and ever, it is the everlasting Gospel.