Here is, 1. David’s petition for divine instruction: “Teach me thy statutes; give me to know all my duty; when I am in doubt, and know not for certain what is my duty, direct me, and make it plain to me; now that I am afflicted, oppressed, and my eyes are ready to fail for thy salvation, let me know what my duty is in this condition.” In difficult times we should desire more to be told what we must do than what we may expect, and should pray more to be led into the knowledge of scripture-precepts than of scripture-prophecies. If God, who gave us his statutes, do not teach us, we shall never learn them. How God teaches is implied in the next petition: Give me understanding (a renewed understanding, apt to receive divine light), that I may know thy testimonies. It is God’s prerogative to give an understanding, that understanding without which we cannot know God’s testimonies. Those who know most of God’s testimonies desire to know more, and are still earnest with God to teach them, never thinking they know enough. 2. His pleas to enforce this petition. (1.) He pleads God’s goodness to him: Deal with me according to thy mercy. The best saints count this their best plea for any blessing, “Let me have it according to thy mercy;” for we deserve no favour from God, nor can we claim any as a debt, but we are most likely to be easy when we cast ourselves upon God’s mercy and refer ourselves to it. Particularly, when we come to him for instruction, we must beg it as a mercy, and reckon that in being taught we are well dealt with. (2.) He pleads his relation to God: “I am thy servant, and have work to do for thee; therefore teach me to do it and to do it well.” The servant has reason to expect that, if he be at a loss about his work, his master should teach him, and, if it were in his power, give him an understanding. “Lord,” says David, “I desire to serve thee; show me how.” If any man resolve to do God’s will as his servant, he shall be made to know his testimonies, John 7:17; Ps. 25:14.