Great deliverance giveth he to his king; and sheweth mercy to his anointed, to David, and to his seed for evermore. Great deliverance giveth he to his king - David was a king of God's appointment, and was peculiarly favored by him. Literally, He is magnifying the salvations of his king. He not only delivers, but follows up those deliverances with innumerable blessings.
Showeth mercy - to David - I have no claim upon his bounty. I deserve nothing from him, but he continues to show mercy.
To his seed - His posterity. So the words זרע zera and σπερμα, in the Old and New Testament, should be universally translated. The common translation is totally improper, and now more so than formerly, when anatomy was less understood.
For evermore - עד עולם ad olam, for ever; through all duration of created worlds. And more - the eternity that is beyond time. This shows that another David is meant, with another kind of posterity, and another sort of kingdom. From the family of David came the man Christ Jesus; his posterity are the genuine Christians; his kingdom, in which they are subjects, is spiritual. This government shall last through all time, for Christianity will continue to prevail till the end of the world: and it will be extended through eternity; for that is the kingdom of glory in which Jesus reigns on the throne of his Father, and in which his followers shall reign with him for ever and ever.
It has already been remarked that this whole Psalm has been understood as relating to the passion and victories of Christ, and the success of the Gospel in the earth. In this way Bishop Horne has understood and paraphrased it; and in the same way it is considered by the ancient Psalter, so often mentioned. Many of the primitive fathers and modern interpreters have taken the same view of it. Those passages which I judged to have this meaning I have pointed out, and have only to add that, as David was a type of Christ, many things spoken of him primarily, refer to our Lord ultimately; but much judgment and caution are required in their application. To apply the whole Psalm in this way appears to me very injudicious, and often derogatory from the majesty of Christ. Let this be my excuse for not following the same track in which many of my predecessors have gone.
Commentary on the Bible, by Adam Clarke [1831].