What does Psalm 25:21 mean?

David refers to integrity and uprightness as the attributes that will preserve him. We do not know whether he was referring to his own attributes or to the Lord's. Certainly, David exhibited both integrity and uprightness (Psalm 7:8; 26:1, 11; 41:12). His enemies were trying to discredit him, but the Lord knew David was righteous. However, in this verse, David may have been appealing to the Lord's integrity and uprightness, not his own.

David certainly could trust the Lord to do what was right and keep him safe. Once again, David states in this verse that he was waiting on the Lord. The word "wait" indicates that David was trustfully expecting the Lord to fulfill His promises. Perhaps he was thinking of the promises the Lord had made to him in his covenant:, to make a great name for David, to give him rest from his enemies, to give him a heritage, and to establish his kingdom forever (a messianic promise) (2 Samuel 7:9–16).