Charles H. Spurgeon on Psalms 119:49

Thy servant. Be sure of your qualification; for David pleadeth here, partly as a servant of God, and partly as a believer. First, "Remember the word unto thy servant; "and then, "upon which thou hast caused me to hope." There is a double qualification: with respect to the precept of subjection, and the promise of dependence. The precept is before the promise. They have right to the promises, and may justly lay hold upon them, who are God's servants; they who apply themselves to obey his precepts, these only can rightly apply his promises to themselves. None can lay claim to rewarding grace but those who are partakers of sanctifying grace. Make it clear that you are God's servants, and then these promises which are generally offered are your own, no less than if your name were inserted in the promise, and written in the Bible. Thomas Manton.