| Barnes' Notes on the Bible So shall I keep thy law continually forever and ever - At all times and in all places; in this world and the world to come. This indicates a purpose to do it, and an assurance that he would do it, if God should enable him to retain even the slightest hold on the truth.
Gill's Exposition of the Entire BibleSo 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.
Geneva Study BibleSo shall I keep thy law continually for ever and ever.
Matthew Henry's Concise Commentary119:41-48 Lord, I have by faith thy mercies in view; let me by prayer prevail to obtain them. And when the salvation of the saints is completed, it will plainly appear that it was not in vain to trust in God's word. We need to pray that we may never be afraid or ashamed to own God's truths and ways before men. And the psalmist resolves to keep God's law, in a constant course of obedience, without backsliding. The service of sin is slavery; the service of God is liberty. There is no full happiness, or perfect liberty, but in keeping God's law. We must never be ashamed or afraid to own our religion. The more delight we take in the service of God, the nearer we come to perfection. Not only consent to his law as good, but take pleasure in it as good for us. Let me put forth all the strength I have, to do it. Something of this mind of Christ is in every true disciple.
Matthew Henry's Whole Bible CommentaryVerses 43-44 Here is, 1. David's humble petition for the tongue of the learned, that he might know how to speak a word in season for the glory of God: Take not the word of truth utterly out of my mouth. He means, "Lord, let the word of truth be always in my mouth; let me have the wisdom and courage which are necessary to enable me both to use my knowledge for the instruction of others, and, like the good householder, to bring out of my treasury things new and old, and to make profession of my faith whenever I am called to it." We have need to pray to God that we may never be afraid or ashamed to own his truths and ways, nor deny him before men. David found that he was sometimes at a loss, that the word of truth was not so ready to him as it should have been, but he prays, "Lord, let it not be taken utterly from me; let my always have so much of it at hand as will be necessary to the due discharge of my duty." 2. His humble profession of the heart of the upright, without which the tongue of the learned, however it may be serviceable to others, will stand us in no stead. (1.) David professes his confidence in God: "Lord, make me ready and mighty in the scriptures, for I have hoped in those judgments of thy mouth, and, if they be not at hand, my support and defence have departed from me." (2.) He professes his resolution to adhere to his duty in the strength of God's grace: "So shall I keep thy law continually. If I have thy word not only in my heart, but in my mouth, I shall do all I should do, stand complete in thy whole will." Thus shall the man of God be perfect, thoroughly furnished for every good word and work, 2 Tim. 3:17; Col. 3:16. Observe how he resolves to keep God's law, [1.] Continually, without trifling. God must be served in a constant course of obedience every day, and all the day long. [2.] For ever and ever, without backsliding. We must never be weary of well-doing. If we serve him to the end of our time on earth, we shall be serving him in heaven to the endless ages of eternity; so shall we keep his law for ever and ever. Or thus: "Lord, let me have the word of truth in my mouth, that I may commit that sacred deposit to the rising generation (2 Tim. 2:2) and by them it may be transmitted to succeeding ages; so shall thy law be kept for ever and ever," that is, from one generation to another, according to that promise (Isa. 59:21), My word in thy mouth shall not depart out of the mouth of thy seed, nor thy seed's seed. | 
