I delight to do Thy will, O God. – Psalm 40:8

Note well, that He came in complete subserviency to His Father, God. “I delight to do”-what? “Thy will.” His own will was absorbed in the divine will. His pleasure it was to say, “Not as I will, but as Thou wilt.” It was His meat and His drink to do the will of Him that sent Him, and to finish His work. Though He was Lord and God, He became a lowly servant for our sakes. Though high as the highest, He stooped low as the lowest. The King of kings was the servant of servants, that He might save His people. He took upon Him the form of a servant, and girded Himself, and stood obediently at His Father’s call.

He had a prospective delight as to His work. Before He came, He delighted in the thought of His incarnation. The Supreme Wisdom saith, “My delights were with the sons of men.” Happy in His Father’s courts, He yet looked forward to an access of happiness in becoming man. “Can that be?” saith one. Could the Son of God be happier than He was? As God, He was infinitely blessed; but He knew nothing by experience of the life of man, and into that sphere He desired to enter. To the Godhead there can be no enlargement, for it is infinite; but still there can be an addition; our Lord was to add the nature of man to that of God. He would live as man, suffer as man, and triumph as man, and yet remain God: and to this He looked forward with a strange delight, inexplicable except upon the knowledge of the great love He bore to us. He had given His heart so entirely to His dear Bride, whom He saw in the glass of predestination, that for her He would endure all things.

“Yea, saith the Lord, for her I’ll go
Through all the depths of care and woe,
And on the cross will even dare
The bitter pangs of death to bear.”

It was wondrous love. Our Lord’s love surpasses all language and even thought. I am talking prodigies and miracles at every word I utter. It was delightful to our Lord to come hither. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/2202.cfm