Their blood shall therefore return upon the head of Joab,
upon the head of his seed for ever
Not only upon Joab, but upon his posterity as long as there would be any; signifying, that Joab's death would not be a sufficient satisfaction, but the punishment of his murders would be continued to his offspring: see ( 2 Samuel 3:29 ) ;
but upon David, and upon his seed, and upon his house, and
throne, shall there be peace for ever from the Lord;
such traitors and murderers being removed, peace and happiness might be expected and believed would attend the family and kingdom of David; whether this be considered as a prayer, or a prophecy, it can and will have its full accomplishment only in the kingdom of the Messiah the son of David, of the increase of whose government, and the peace thereof, there shall be no end, ( Isaiah 9:7 ) ( Psalms 72:7 ) .