Luke 4:3

When a father is asked by his son for bread, he does not give him a stone for bread, but the devil like a crafty and deceitful foe gives stones for bread. I suppose also that even now at this very time the devil shows a stone to men that he may tempt them to speak, saying to them, Command this stone to be made bread. If thou seest the heretics devouring their lying doctrines as if they were bread, know that their teaching is a stone which the devil shows them.

(ubi sup.) He tried to persuade Christ to satisfy His appetite with stones, i. e. to shift his desire from the natural food to that which was beyond nature or unnatural.

You see then what kind of arms He uses to defend man against the assaults of spiritual wickedness, and the allurements of the appetite. He does not exert His power as God, (for how had that profited me,) but as man He summons to Himself a common aid, that while intent upon the food of divine reading He may neglect the hunger of the body, and gain the nourishment of the word. For he who seeks after the word cannot feel the want of earthly bread; for divine things doubtless make up for the loss of human. At the same time by saying, Man lives not by bread alone, He shows that man was tempted, that is, our flesh which He assumed, not His own divinity.

There are three especial weapons which we are taught the devil is wont to arm himself with, that he may wound the soul of man. One is of the appetite, another of boasting, the third ambition. He began with that wherewith he had already conquered, namely, Adam. Let us then beware of the appetite, let us beware of luxury, for it is a weapon of the devil. But what mean his words, If thou art the Son of God, unless he had known that the Son would come, but supposed Him not to have come from the weakness of His body. He first endeavours to find Him out, then to tempt Him. He professes to trust Him as God, then tries to deceive Him as man.

(ubi sup.) But because not to suffer hunger is above the nature of man, our Lord took upon Himself the feeling of hunger, and submitted Himself as it pleased Him to human nature, both to do and to suffer those things which were His own. Hence it follows: And those days being ended, he was a hungered. Not forced to that necessity which overpowers nature, but as if provoking the devil to the conflict. For the devil, knowing that wherever hunger is there is weakness, sets about to tempt Him, and as the deviser or inventer of temptations, Christ permitting him tries to persuade Him to satisfy His appetite with the stones. As it follows; But the devil said unto him, If thou art the Son of God, command these stones that they be made bread.