Thou hast given him his heart's desire, and hast not withholden the request of his lips. Selah. Thou hast given him his heart's desire - This seems to refer to the prayers offered in the preceding Psalm; see especially Psalms 21:1-4.
Related Commentaries of Psalms 21:2
Psalms 21:2
2 Thou hast given him his heart's desire, and hast not withholden the request of his lips. Selah.