For ever and ever. — This is merely a term for indefinite length. (Comp. the common salutation of a king: 1 Kings 1:31; Nehemiah 2:3; Daniel 3:9.) An allusion to the eternal kingdom of the Messiah is not to be forced on the passage.
Related Commentaries of Psalms 21:4
Psalms 21:4
4 He asked life of thee, and thou gavest it him, even length of days for ever and ever.