I think probably what strikes us as most difficult to deal with is the reasoning that David gives for God to mercifully raise him up. He wants God’s help so that he can pay these enemies of his back!
Vengeance is God's
And this can be a little confusing to us. After all, we know that God has promised that vengeance is his – he will repay. And therefore, we’re supposed to leave room for the wrath of God and not take our own vengeance.
David was not a vengeful man
And actually – from David’s own life we see that so often he was not in the practice of paying people back immediately for wrongs done to him.
Kings do need to take vengeance on evildoers
And yet – as king, David would need to repay people for wrongs done. That was his job. If these people were breaking God’s laws he was tasked with enforcing those laws and punishing wrongdoing.
David was king
I think that’s what David is getting at. This would be his job as king to avenge evildoing. To pay back those who commit crime.
Psalm 41:10 might apply to Christ and Judas
In addition, if what David says in verse 10 applies to Christ and his relationship with Judas – think about it. Christ was raised up from the dead. And it’s that fact that will allow him to requite Judas eternally.
So, there’s an aspect where verse 10 can apply to both David and Christ.