Delight yourself also in the LORD and He shall give you the desires of your heart. Psalms 37:4
Psalms 37 verses 3 and 5 clearly refer to those whose desires are in harmony with those of God. A person who delights in the Lord has righteous desires. He will not desire anything that is evil. We cannot expect God to give us something that is not according to His will and for His glory. This idea is expressed often in the book of Psalms.
The Lord Jesus is the perfect example of a man who delighted Himself in the Lord. He delighted Himself in His Father throughout His life, and even bore our sins on the cross. He said that I do not seek My own will but the will of the Father who sent Me. When the will of man is aligned with the will of God, then the things that delight our Heavenly Father will naturally become the joy of our own heart.