Then I said, “Behold, I have come (in the volume of the book it is written of Me) to do Your will, O God.” – Hebrews 10:7

“Sacrifice and offering Thou didst not desire. Then said I, Lo, I come.” Observe when He says this. It is in the time of failure. All the sacrifices had failed. The candle flickered, and was dying out, and then the great light arose, even the eternal light, and like a trumpet the words rung out, “Lo, I come. All this has been of no avail; now I come.” It is in the time of failure that Christ always does appear. The last of man is the first of God; and when we have come to the end of all our power and hope, then the eternal power and Godhead appears with “Lo, I come.”

When He appears, it is as the personal Lord. Lay the stress upon the pronoun, “Lo, I come.” The infinite Ego appears. “Lo, I come.” No mere man could talk thus, and be sane. No servant or prophet of God would ever say, “Lo, I come.” Saintly men talk not so. God’s prophets and apostles have a modest sense of their true position: they never magnify themselves, though they magnify their office. It is for God to say, “Lo, I come.” He who says it takes the body prepared for Him, and comes in His own proper personality as the I AM. “In Him dwelleth all the fullness of the Godhead bodily.” He comes forth from the ivory palaces to inhabit the tents of manhood. He takes upon Himself the body prepared for Him of the Lord God, and He stands forth in His matchless personality ready to do the will of God…”Lo, I come.” This is no dirge: I think I hear a silver trumpet ring out-“Lo, I come.” Here is a joyful alacrity and intense eagerness. The coming of the Savior was to Him a thing of exceeding willingness. “For the joy that was set before Him He endured the cross, despising the shame.”~ C.H. Spurgeon

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