Here, I. David prays earnestly that God himself would be his teacher; he had prophets, and wise men, and priests, about him, and was himself well instructed in the law of God, yet he begs to be taught of God, as knowing that none teaches like him, Job 36:22. Observe here, 1. What he desires to be taught, not the notions or language of God's statutes, but the way of them - "the way of applying them to myself and governing myself by them; teach me the way of my duty which thy statutes prescribe, and in every doubtful case let me know what thou wouldst have me to do, let me hear the word behind me, saying, This is the way, walk in it" Isa 30:21. 2. How he desires to be taught, in such a way as no man could teach him: Lord, give me understanding. As the God of nature, he has given us intellectual powers and faculties; but here we are taught to pray that, as the God of grace, he would give us understanding to use those powers and faculties about the great things which belong to our peace, which, through the corruption of nature, we are averse to: Give me understanding, an enlightened understanding; for it is as good to have no understanding at all as not to have it sanctified. Nor will the spirit of revelation in the word answer the end unless we have the spirit of wisdom in the heart. This is that which we are indebted to Christ for; for the Son of God has come and has given us understanding, Jo1 5:20.
II. He promises faithfully that he would be a good scholar. If God would teach him, he was sure he should learn to good purpose: "I shall keep thy law, which I shall never do unless I be taught of God, and therefore I earnestly desire that I may be taught." If God, by his Spirit, give us a right and good understanding, we shall be, 1. Constant in our obedience: "I shall keep it to the end, to the end of my life, which will be the surest proof of sincerity." It will not avail the traveller to keep the way for a while, if he do not keep it to the end of his journey. 2. Cordial in our obedience: I shall observe it with my whole heart, with pleasure and delight, and with vigour and resolution. That way which the whole heart goes the whole man goes; and that should be the way of God's commandments, for the keeping of them is the whole of man.

Incline my heart unto thy testimonies,.... To read the word of God, to hear it opened and explained, to observe and keep the things contained in it; to which there is a disinclination in men naturally: but the Lord, who fashions the hearts of men, and has them in his hands, can bend and incline them by his efficacious grace to regard these his testimonies; which, as Aben Ezra observes, are more precious than all substance, and so are opposed to what follows:

and not to covetousness; not to mammon or money, as the Targum; the love of it, which is the root of all evil, and very pernicious and harmful; in hearing the word it chokes it, and makes it unfruitful, Ti1 6:9. Not that God inclines the heart to evil, as he does to good; but he may suffer the heart to be inclined, and may leave a man to the natural inclinations of his heart, and to the temptations of Satan, and the snares of the world, which may have great influence upon him; and this is what is here deprecated; see Psa 141:4.