III. Jesus Christ is promised for the making good of all the other promises which we are here invited to accept of, v. 4. He is that David whose sure mercies all the blessings and benefits of the covenant are. "And God has given him in his purpose and promise, has constituted and appointed him, and in the fulness of time will as surely send him as if he had already come, to be all that to us which is necessary to our having the benefit of these preparations." He has given him freely; for what more free than a gift? There was nothing in us to merit such a favour, but Christ is the gift of God. We want one, 1. To attest the truth of the promises which we are invited to take the benefit of; and Christ is given for a witness that God is willing to receive us into his favour upon gospel terms, to confirm the promises made unto the fathers, that we may venture our souls upon those promises with entire satisfaction. Christ is a faithful witness, we may take his word—a competent witness, for he lay in the bosom of the Father from eternity, and was perfectly apprised of the whole matter. Christ, as a prophet, testifies the will of God to the world; and to believe is to receive his testimony. 2. To assist us in closing with the invitation, and coming up to the terms of it. We know not how to find the way to the waters where we are to be supplied, but Christ is given to be a leader. We know not what to do that we may be qualified or it, and become sharers in it, but he is given for a commander, to show us what to do and enable us to do it. Much difficulty and opposition lie in our way to Christ; we have spiritual enemies to grapple with, but, to animate us for the conflict, we have a good captain, like Joshua, a leader and commander to tread our enemies under our feet and to put us in possession of the land of promise. Christ is a commander by his precept and a leader by his example; our business is to obey him and follow him.