Then the devil said to Him, "If You are the Son of God, tell this stone (Matt: these stones) to become a loaf (Matt: loaves) of bread."
This is an interesting change to say the least. Why would Luke change loaves --> loaf and stones --> stone? I have to confess to not being sure what is behind the change. Except to note that the words are quoted from satan's mouth. There are several strands running through this image and it is hard to disentangle them. So I will begin this now, live and maybe you can add ideas as we go.
The form of bread talked about was in flat round loaves. So as such they would have resembled flat stones. By pointing out one loaf rather than all loaves it seems to infer that one loaf was in focus. I.e. This loaf as opposed to the others too. But there is no antecedent for a focus on just one loaf in the context of the discussion. It is possible that satan was indicating all the stones instead of one and challenging Jesus to turn them all to bread. But if that were the case then clearly it would be far more than He would require. In this case He is not feeding 5,000, only Himself. Is satan challenging Him to an excessive demonstration of His power far more than he needs? Extravagant and flamboyant use of His power. It is hard to say.
What is interesting is that there is a connection to this in the Old Testament. The reference that comes immediately to mind is that of the provision of manna in the wilderness. Here, Jesus is found in the wilderness again and is being challenged to provide a heap of "bread" just like was done for the children of Israel in the wilderness in Moses day. But there is no reason to do that because only Jesus is hungry and furthermore there are no witnesses to such an act. It is like satan is challenging the Messiah to demonstrate His Messiahship in a frivolous way.
Another way of looking at this in the context of the challenge satan has issued. "If You are the Son of God". . . In essence saying prove you are this son of God. So this is a dispersion cast on the Messiah as to whether He is able to do it. In which case the focus on many stones rather than just one. Turn all these stones to bread. Go on, do it. Use your superpowers to prove to me you are who they say you are. But as we shall see when we look at "If you are the Son of God", satan knows full well who He is. Satan is in doubt that He is indeed the Son of God. The One Luke points to in his genealogy of this Jesus.
Still another way of looking at it is that Jesus is being challenged by satan to use His super natural power for His own satisfaction. To step out from His role as Messiah to meet His own need; to ease "the suffering" that He is feeling at the moment . If that is the case then the use of "stone" instead of "stones" and "loaf" instead of loaf makes perfect sense. This after all is a challenge to Jesus to take this one stone and turn it into a loaf of bread. To reject "doing only what the Father wills" in order to meet his own selfish need. The kind of thing the first Adam / man would do; not the second Adam / man. If that is the case this is a veiled attempt to distract Jesus from doing only what the Father wills believing that the Father didn’t care about His hunger and He had to take care of this matter himself. The Father had brought Him to this hunger for His (the Father's) purpose. Was Jesus now to look down and use these stones to create some "manna" for Himself because He can?
Typically sneaky of the devil perhaps to mix the two concepts. This approach challenging the concept of only doing the Father's will, the turning many stones into loaves to demonstrate His powers, thus forsaking the Father's will just for this one moment. Is Satan attempting to incite Jesus hunger as a means to stir His dissatisfaction, His impatience and His desire to want His own way, to meet His need in His own time and His own way? Satan appears to be attempting to reduce Jesus to the likes of one of us.
I suspect this change has deep significance but I am not sure I have found what it is yet. All of these things I have commented on above are true but I am not sure I know yet why Luke specifically changed what Matthew had recorded in his gospel. Or was it that he changed the standard use of the plural form in the oral tradition to a singular use in his gospel to make a particular point? And if so what is it? I still have to think some more on this. But I offer it to you too for your own interest and study. Feel free to share your insights if you get any.
You haven't really trusted God until you've attempted something that you cannot do in your own strength. Rick Warren
If you only try the things you know are possible with the resources you possess, you'll receive the credit and God will have no part in it. Bob Gass
Next time you're tempted, Tell Satan he's talking to a corpse.