Charles H. Spurgeon on Psalms 27:7

Hear, O Lord, when I cry with my voice. The pendulum of spirituality swings from prayer to praise. The voice which in the last verse was tuned to music is here turned to crying. As a good soldier, David knew how to handle his weapons, and found himself much at home with the weapon of "all prayer." Note his anxiety to be heard. Pharisees care not a fig for the Lord's hearing them, so long as they are heard of men, or charm their own pride with their sounding devotions; but with a genuine man, the Lord's ear is everything. The voice may be profitably used even in private prayer; for though it is unnecessary, it is often helpful, and aids in preventing distractions. Have mercy also upon me. Mercy is the hope of sinners and the refuge of saints. All acceptable petitioners dwell much upon this attribute. And answer me. We may expect answers to prayer, and should not be easy without them any more than we should be if we had written a letter to a friend upon important business, and had received no reply.