Here, 1. David applies to God for grace and comfort with much solemnity. He begs of God to hear his voice: "Lord, I have something to say to thee; shall I obtain a gracious audience?" Well, what has he to say? What is his petition and what is his request? It is not long, but it has much in a little: "Lord, quicken me; stir me up to that which is good, and make me vigorous, and lively, and cheerful in it. Let habits of grace be drawn out into act." 2. He encourages himself to hope that he shall obtain his request; for he depends, (1.) Upon God's lovingkindness: "He is good, therefore he will be good to me, who hope in his mercy. His lovingkindness manifested to me will help to quicken me, and put life into me." (2.) Upon God's judgment, that is, his wisdom ("He knows what I need, and what is good for me, and therefore will quicken me"), or his promise, the word which he has spoken, mercy secured by the new covenant: Quicken me according to the tenour of that covenant.