Or what man is there of you,
Who, if his son shall ask him for a loaf,
Will give him a stone;
Or if he will ask for a fish,
Will give him a serpent?
He then gives them examples in order to strengthen their faith and confidence in their Father. God is their heavenly Father, so let them first consider what an earthly father would do. What earthly father, if asked for bread would give a stone to his son? We have already seen how stones can be likened to the small round loaves baked by the Jews (Matthew 4:3). What a callous father it would be who would give a stone to his hungry son, pretending that it was bread. Or what earthly father, if asked for a fish would give him a snake that looks at first sight like an edible fish (probably the snake-like catfish of the Sea of Galilee) but is far from being so? The answer in both cases is that such a thing is totally beyond belief. Even more so is it then beyond belief with their heavenly Father.
It may be significant that both the false gifts can be associated with Satan. Perhaps Jesus had in mind here what had been offered to Him when He was praying. It was Satan who offered stones to Jesus instead of bread (Matthew 4:3), and it was as the Serpent of old (Revelation 12:9) that he came to Him on the high mountain offering Him good things, such gifts as honour, and prestige and power. Such gifts come from Satan not the Father. The Father has only good things to give to His children, not the baubles of the world. Alternately the ‘snake' may have indicated an eel, which being ‘unclean' a Jewish son should not eat.