Psalms 71:17

17.O God! thou hast taught me from my youth. The Psalmist again declares the great obligations under which he lay to God for his goodness, not only with the view of encouraging himself to gratitude, but also of exciting himself to continue cherishing hope for the time to come: which will appear from the following verse. Besides, since God teaches us both by words and deeds, it is certain that the second species of teaching is here referred to, the idea conveyed being, that David had learned by continual experience, even from his infancy, that nothing is better than to lean exclusively upon the true God. That he may never be deprived of this practical truth, he testifies that he had made great proficiency in it. When he promises to become a publisher of God’s wondrous works, his object in coming under this engagement is, that by his ingratitude he may not interrupt the course of the Divine beneficence.

Upon the truth here stated, he rests the prayer which he presents in the 18th verse, that he may not be forgotten in his old age. His reasoning is this: Since thou, O God! hast from the commencement of my existence given me such abundant proofs of thy goodness, wilt thou not stretch forth thy hand to succor me, when now thou seest me decaying through the influence of old age? And, indeed, the conclusion is altogether inevitable, that as God vouchsafed to love us when we were infants, and embraced us with his favor when we were children, and has continued without intermission to do us good during the whole course of our life, he cannot but persevere in acting toward us in the same way even to the end. Accordingly, the particle גם, gam, which we have translated still, here signifies therefore; it being David’s design, from the consideration that the goodness of God can never be exhausted, and that he is not mutable like men, to draw the inference that he will be the same towards his people in their old age, that he was towards them in their childhood. He next supports his prayer by another argument, which is, that if he should fail or faint in his old age, the grace of God, by which he had been hitherto sustained, would at the same time soon be lost sight of. If God were immediately to withdraw his grace from us after we have but just tasted it slightly, it would speedily vanish from our memory. In like manner, were he to forsake us at the close of our life, after having conferred upon us many benefits during the previous part of it, his liberality by this means would be divested of much of its interest and attraction. David therefore beseeches God to assist him even to the end, that he may be able to commend to posterity the unintermitted course of the Divine goodness, and to bear testimony, even at his very death, that God never disappoints the faithful who betake themselves to him. By the generation and those who are to come, he means the children and the children’s children to whom the memorial of the loving-kindness of God cannot be transmitted unless it be perfect in all respects, and has completed its course. He mentions strength and power as the effects of God’s righteousness. He is, however, to be understood by the way as eulogising by these titles the manner of his deliverance, in which he congratulates himself; as if he had said, that God, in the way in which it was accomplished, afforded a manifestation of matchless and all-sufficient power.