What does Psalm 22:25 mean?

The Lord is the ultimate source of praise, since He is the giver of all good things (1 Timothy 4:4; James 1:16–17). God has given David good reason to praise. He promises to fulfill the vows he made to the Lord. Apparently, when he was surrounded by his enemies and death loomed large, David made some vows to the Lord. He likely promised the Lord what service he would perform if the Lord delivered him. Now that he is delivered, he plans to perform those vows in the sight of those who reverence God.

In doing so, David would honor the exhortation of Numbers 30:2: "If a man vows a vow to the LORD, or swears an oath to bind himself by a pledge, he shall not break his word. He shall do according to all that proceeds out of his mouth." In times of trouble a person may vow to serve God or to turn over a new leaf if the Lord rescues him or her. Unfortunately, the person may forget to honor the vow. Of course, we are in no position to bargain with God; we cannot make deals with Him as if to buy His blessings. However, we must be careful about making vows, so if we make them, we ought to keep them.