What does Psalm 20:4 mean?

This continues a congregational prayer on behalf of King David. The people pray God will give David what his heart desires and bring David's plans to a successful conclusion.

Proverbs 3:5–6 promises if we fully trust in the Lord, and accept His will, He will guide us. David had not depended upon his own understanding as he prepared for battle. He had worshiped the Lord and sought His will (1 Samuel 23:1–2). The word "plans" as translated here is from the Hebrew term asāt, which can also be rendered as "strategies, counsel, or advice." David's battle strategies for defeating the enemy would be successful if the Lord fulfilled them.

The apostle James counsels us not to plan what we will do tomorrow without seeking God's will (James 4:13–15). The Lord instructed Joshua to meditate on the Word of God and obey the God of the Word and then he would be successful (Joshua 1:4–9).