Psalm 40:8:
I delight to do your will O my God, your law is within my heart.
How often have we heard, or been taught that to do the will of God is difficult, even grievous. We have images in our mind that to say "yes" to God means living in a grass or mud hut in some desolate country or island. This verse is telling us that when God's Word is in our heart, it is a delight to do the will of God.
The Hebrew word for “will” is ratson. It means pleasurable or even joyous. Do you understand what this verse is saying? It is even joyous for God to see us accomplish His will. The will of God is joyous in God's sight and a delight for us to do. This verse is really a play on words. "O my God, I get happy when I make you happy."
Quit thinking of sorrow and begin to imagine having the time of your life doing God's will. If you accept God's will for the moment, or even your life, He drops the desire to do it in your heart. His yoke is easy and His burden is light.