Verse 17. - O God, thou hast taught me from my youth: and hitherto have I declared thy wondrous works. Hitherto, i.e., have I always had thy guidance and instruction, and hitherto have I always had occasion to praise thy Name. Hence I am confident with respect to the future.

71:14-24 The psalmist declares that the righteousness of Christ, and the great salvation obtained thereby, shall be the chosen subject of his discourse. Not on a sabbath only, but on every day of the week, of the year, of his life. Not merely at stated returns of solemn devotion, but on every occasion, all the day long. Why will he always dwell on this? Because he knew not the numbers thereof. It is impossible to measure the value or the fulness of these blessings. The righteousness is unspeakable, the salvation everlasting. God will not cast off his grey-headed servants when no longer capable of labouring as they have done. The Lord often strengthens his people in their souls, when nature is sinking into decay. And it is a debt which the old disciples of Christ owe to succeeding generations, to leave behind them a solemn testimony to the advantage of religion, and the truth of God's promises; and especially to the everlasting righteousness of the Redeemer. Assured of deliverance and victory, let us spend our days, while waiting the approach of death, in praising the Holy One of Israel with all our powers. And while speaking of his righteousness, and singing his praises, we shall rise above fears and infirmities, and have earnests of the joys of heaven. The work of redemption ought, above all God's works, to be spoken of by us in our praises. The Lamb that was slain, and has redeemed us to God, is worthy of all blessing and praise.O God, thou hast taught me from my youth,.... The corruption of human nature; the weakness and impotence of it, to everything that is spiritually good; and the need of continual strength and grace from Christ, to go to him for righteousness and strength, life and salvation, and to walk by faith on him; the doctrine of justification by the righteousness of Christ, and the insufficiency of his own; the will, ways, and worship of God; and all the duties of religion, prayer, praise, &c. and whoever were the instruments, or whatever were the means, of teaching David these things, he ascribes it to God. Whether his parents, or the priests and Levites, taught him the sacrifices and ordinances of the law, it was the Lord that blessed instructions to him; and that taught him by providences and precepts, and by his Holy Spirit. And a wonderful blessing it is to be taught of God, and not of men, things relating both to doctrine and practice; and it is an addition to it to be taught these things early, as David was from his youth; and therefore the Lord was so soon the object of his faith and trust, Psalm 71:5; and, as Timothy, from a child, was acquainted with the holy Scriptures, and the things contained in them, which are able to make wise unto salvation, Isaiah 29:13;

and hitherto have I declared thy wondrous works: not only of nature and providence, but of grace; the treasuring up of all grace, and the blessings of it in Christ; the work of redemption by him; the work of regeneration and conversion by his Spirit; and the perseverance of the saints by his grace and strength; which are all wonderful and amazing. And as the psalmist saw his interest in these things, and had an experience of them, he declared them to others for their encouragement, and to the glory of all the three Persons; see Psalm 66:16.