Psalms 21:4

He asked life of thee, and thou gavest it him,....

"He asked life of thee, and thou gavest it him, even length of days for ever and ever." The first words may suit King David, but the length of days for ever and ever can only refer to the King Messiah. Jesus, as man, prayed for resurrection and he received it, and now possesses it in immortality. He died once, but being raised from the dead he dieth no more. "Because I live, ye shall live also, " is the delightful intimation which the Saviour gives us, that we are partakers of his eternal life.

The glory and blessedness of the king as head of his line, including Christ, as well as in being God's specially selected servant, exceeded that of all others.

He asked life of thee - This verse has caused some interpreters to understand the Psalm of Hezekiah’s sickness, recovery, and the promised addition to his life of fifteen years; but it may be more literally understood of the Messiah, of whom David was the type, and in several respects the representative.

He asked life of thee - An expression similar to this occurs in Psa 61:5-6, “For thou, O God, hast heard my vows;...Thou wilt prolong the king’s life, and his years to many generations.” The expression in both cases implies that there had been a prayer for “life,” as if life were in danger. The expression itself would be applicable to a time of sickness, or to danger of any kind, and here it is used doubtless in reference to the exposure of life in going into battle, or in going forth to war. In this apprehended peril he prayed that God would defend him. He earnestly sought protection as he went forth to the perils of war. And thou gavest it him - Thou didst hear and answer his prayer. He was saved from danger. Even length of days forever and ever - Thou didst grant him more than he asked. He sought life for himself; thou bast not only granted that, but hast granted to him the assurance that he should live in his posterity to all generations. The idea is, that there would be an indefinite contination of his race. His posterity would occupy his throne, and there would be no end to his reign thus prolonged. Beyond all his petitions and his hopes, God bad given the assurance that his reign would be permanent and enduring. We cannot suppose that he understood this as if it were a promise made to him personally, that “he” would live and would occupy the throne forever; but the natural interpretation is that which would refer it to his posterity, and to the perpetuity of the reign of his family or descendants. A similar promise occurs elsewhere: 2Sa 7:13, 2Sa 7:16; compare the notes at Psa 18:50. It is by no means an uncommon thing that God gives us more than we asked in our prayers. The offering of prayer is not only the means of securing the blessing which we asked, but also often of securing much more important blessings which we did not ask. […]