In this psalm David sets forth the perpetuity of Christ's reign, and the eternity of his priesthood; and, in the first place, he affirms, That God conferred upon Christ supreme dominion, combined with invincible power, with which he either conquers all his enemies, or compels them to submit to him. In the second place, he adds, That God would extend the boundaries of this kingdom far and wide; and, in the third place, That Christ, having been installed into the priestly office with all the solemnity of an oath, sustains the honors of that equally with those of his regal office. Finally, That this shall be a new order of priesthood, whose introduction shall put an end to the Levitical priesthood, which was temporary, and that it shall be everlasting.
A Psalm of David.
Having the testimony of Christ that this psalm was penned in reference to himself, we need not apply to any other quarter for the corroboration of this statement; and, even supposing we neither had his authority, nor the testimony of the apostle, the psalm itself would admit of no other interpretation; for although we should have a dispute with the Jews, the most obstinate people in the world, about the right application of it, we are able, by the most irresistible arguments, to compel them to admit that the truths here stated relate neither to David nor to any other person than the Mediator alone. It is acknowledged that the kingdom of Christ is typified in the person of David, but it cannot be asserted of him, or of any of his successors, that he should be a king whose dominion should be widely extended, and who, at the same time, was to be a priest, not according to the law, but according to the order of Melchizedek, and that for ever; for, at that time, no new and unusual priestly dignity could be instituted, without depriving the house of Levi of this peculiar honor. Besides, the perpetuity which is ascribed to the sacerdotal office cannot belong to any man, because, with the exception of the man Christ Jesus, this honor terminates immediately at the close of the short and uncertain course of the present life. But as these topics will be considered, more at large, in their proper place, it is sufficient that we have, at this time, briefly alluded to them.