If a son shall ask bread of any of you that is a father, will he give him a stone? or if he ask a fish, will he for a fish give him a serpent? Or if he shall ask an egg, will he offer him a scorpion?
If ye then, being evil, know how to give good gifts unto your children: how much more shall your heavenly Father give the Holy Spirit to them that ask him? Luke 11:11-13
"Bread in the East is not like what you are familiar with in the western world. Each piece is round and flat, about the size of a dinner plate. It is very thin and is cooked on both sides. . . When the bread is done it is placed on a stone which is about the same size as the bread. Ordinarily there would be several [loaves] in one stack. Then another stone would be placed on top to protect the bread. The women use ghee, which is [clarified] butter, in cooking the bread. Over a period of time the stones soak up the ghee and actually take on the appearance of the bread. . . Obviously, any Eastern father would know the difference between the stone and the bread, and he would never give the stone when his son has asked for bread."
"There are all kinds of fish in Eastern waters, and there are many serpents which look like fish. One who is unfamiliar with the fish and the serpents could easily mistake one for the other. But the Eastern fisherman knows the difference and will throw out of the net all serpents or anything else that is not fit for human consumption. The father would not think of giving his son a serpent instead of a fish."
"The body of a scorpion looks like an egg. The white scorpion, especially, could be mistaken for an egg. And if one would cut open its body, the inside is white and yellow just like an egg. So, you see, it is conceivable that a child would not know the difference. But his father knows, and the son has absolute confidence that he would not give anything that would harm him."
"The whole point is that Father knows best. . . There is also another lesson we can learn from this scripture: nothing that is harmful to us comes from God. He is more concerned about his children than earthly fathers are for theirs."
Reverend Dr. K.C. Pillai Orientalisms in the Bible