The Spirit of God led Jesus Christ to fast in the desert for forty days and forty nights. There, He was tempted by Satan physically, psychologically, and spiritually. Jesus was hungry when the tempter came and said, "If thou be the Son of God, command this stone that it be made bread." Jesus' response was, "It is written, That man shall not live by bread alone, but by every word of God."
Jesus was confessing, "The Spirit led Me here into the wilderness, and I have the two-edged Sword in My mouth and in My hand. Yes, I am hungry. I have a tremendous need. But, I will base everything that I think on ‘It is written.'"
Next came a spiritual attack, when Satan offered Jesus the kingdoms of the world in return for a moment of worship from the Son of God. Jesus resisted Satan with "It is written."
Then, Satan applied psychological pressure by setting Him on the pinnacle of the temple, and daring Jesus to cast Himself down. The devil twisted the scriptures. But, Jesus answering said unto him, "It is said, Thou shalt not tempt the Lord thy God" (Luke 4:10-12).
Jesus fought off all these temptations with "It is written."