Psalm 21:4:

He [King David] asked life of thee, and thou gavest it him, even length of days for ever and ever.

Notes on Psalm 21:4:

King David asked for long life and got it in spite of all the wrongs he did.  How much more should you be able to do so!  Every Bible reader is aware of the glaring shortcomings in David’s life, but he knew how to repent, and God blotted out his sins.  Thus, he had every right to ask for long life.  So do you, because you are the righteousness of God in Christ.  Your sins are blotted out too!