He had before prayed to God to enlighten his understanding, that he might know his duty, and not mistake concerning it; here he prays to God to bow his will, and quicken the active powers of his soul, that he might do his duty; for it is God that works in us both to will and to do, as well as to understand, what is good, Phil. 2:13. Both the good head and the good heart are from the good grace of God, and both are necessary to every good work. Observe here,
I. The grace he prays for. 1. That God would make him able to do his duty: “Make me to go; strengthen me for every good work.” Since we are not sufficient of ourselves, our dependence must be upon the grace of God, for from him all our sufficiency is. God puts his Spirit within us, and so causes us to walk in his statutes (Ezek. 36:27), and this is that which David here begs. 2. That God would make him willing to do it, and would, by his grace, subdue the aversion he naturally had to it: “Incline my heart to thy testimonies, to those things which thy testimonies prescribe; not only make me willing to do my duty, as that which I must do and therefore am concerned to make the best of, but make me desirous to do my duty as that which is agreeable to the new nature and really advantageous to me.” Duty is then done with delight when the heart is inclined to it: it is God’s grace that inclines us, and the more backward we find ourselves to it the more earnest we must be for that grace.
II. The sin he prays against, and that is covetousness: “Incline my heart to keep thy testimonies, and restrain and mortify the inclination there is in me to covetousness.” That is a sin which stands opposed to all God’s testimonies; for the love of money is such a sin as is the root of much sin, of all sin. Those therefore that would have the love of God rooted in them must get the love of the world rooted out of them; for the friendship of the world is enmity with God. See in what way God deals with men, not by compulsion, but he draws with the cords of a man, working in them an inclination to that which is good and an aversion to that which is evil.
III. His plea to enforce this prayer: “Lord, bring me to, and keep me in, the way of thy commandments, for therein do I delight; and therefore I pray thus earnestly for grace to walk in that way. Thou hast wrought in me this delight in the way of thy commandments; wilt thou not work in me an ability to walk in them, and so crown thy own work?”