Here is, 1. David in care to be found in the way of his duty. His constant desire and design are to keep the testimony of God’s mouth, to keep to it as his rule and to keep hold of it as his confidence and portion for ever. This we must keep, whatever we lose. 2. David at prayer for divine grace to assist him therein: “Quicken me after thy lovingkindness (make me alive and make me lively), so shall I keep thy testimonies,” implying that otherwise he should not keep them. We cannot proceed, nor persevere, in the good way, unless God quicken us and put life into us; we are therefore here taught to depend upon the grace of God for strength to do every good work, and to depend upon it as grace, as purely the fruit of God’s favour. He had prayed before, Quicken me in thy righteousness (Ps. 119:40); but here, Quicken me after thy lovingkindness. The surest token of God’s good-will toward us is his good work in us.