Luke 4.3-4: The devil said to him, “If you are the Son of God, command this stone to become bread.” (4) And Jesus answered him, “It is written, ‘Man shall not live by bread alone.'” (ESV)
At the conclusion of the 40 days of Jesus’ time of consecration and devotion to God, the devil implemented his strategy and made his approach to Jesus for the purpose of enticing Jesus to sin. The devil went at Jesus from the angle of Jesus’ greatest condition of physical weakness in that he was so hungry. And there was no food available.
But the devil had another idea. Namely, appeal to Jesus to use the divine power of his spoken word and solve the problem himself. When the devil challenged Jesus to speak to the stone and turn it into bread, he appealed to the fact that Jesus is God. When the devil proposed, “if you are the Son of God”, the “if” that he spoke was in such a way as to affirm or concede that Jesus is the Son of God. This expression could also be translated, “since you are the Son of God”.
But Jesus would not use his speaking power for his own benefit. He would not give in to the temptation to satisfy his physical need of the moment by using his divine power. Jesus rejected this temptation by trusting in the word of God written in Deuteronomy 8.3: “that man does not live by bread alone, but man lives by everything that proceeds out of the mouth of the LORD.” (NASB). The Gospel of Matthew account of this event sets forth a fuller quotation by Jesus of this verse. So Jesus will live by trusting the word of God.