Complete Commentary on the Whole Bible, by Matthew Henry, at sacred-texts.com
(Psa 143:1-6) David complains of his enemies and distresses.
(Psa 143:7-12) He prays for comfort, guidance, and deliverance.
We have no righteousness of our own to plead, therefore must plead God's righteousness, and the word of promise which he has freely given us, and caused us to hope in. David, before he prays for the removal of his trouble, prays for the pardon of his sin, and depends upon mercy alone for it. He bemoans the weight upon his mind from outward troubles. But he looks back, and remembers God's former appearance for his afflicted people, and for him in particular. He looks round, and notices the works of God. The more we consider the power of God, the less we shall fear the face or force of man. He looks up with earnest desires towards God and his favour. This is the best course we can take, when our spirits are overwhelmed. The believer will not forget, that in his best actions he is a sinner. Meditation and prayer will recover us from distresses; and then the mourning soul strives to return to the Lord as the infant stretches out its hands to the indulgent mother, and thirsts for his consolations as the parched ground for refreshing rain.
David prays that God would be well pleased with him, and let him know that he was so. He pleads the wretchedness of his case, if God withdrew from him. But the night of distress and discouragement shall end in a morning of consolation and praise. He prays that he might be enlightened with the knowledge of God's will; and this is the first work of the Spirit. A good man does not ask the way in which is the most pleasant walking, but what is the right way. Not only show me what thy will is, but teach me how to do it. Those who have the Lord for their God, have his Spirit for their Guide; they are led by the Spirit. He prays that he might be enlivened to do God's will. But we should especially seek the destruction of our sins, our worst enemies, that we may be devotedly God's servants.