with that sign, or when he confronted the sorcerers so that it swallowed up their ropes and staffs. The same sequence held for all his other signs: Pharaoh himself was not drowned until the army had set out and Moses struck the sea with his staff; water did not burst forth from the rock until he struck it with his staff and his people begged him for water while they were in a barren wilderness with nothing to drink.
The signs granted to our Prophet (peace and blessings be upon him) followed the same principle. When water was multiplied, it was after he placed his hand in the vessel until water sprang from between his fingers—that is, it surged between the fingers, not from the fingers themselves. The water of a well would increase either when he cast an arrow from his quiver into it or when he poured into it water into which he had spat. Likewise, Jesus the Messiah would fashion a bird-shaped figure from clay, breathe into it, and it would become a living bird by Allah’s permission, and so forth.
By contrast, a mountain’s suddenly turning into ruby with no preceding causes has never happened and will never happen; the same holds for a flowing river’s becoming milk without causes created by Allah that bring that about—this has never occurred and will not occur.
When someone says that a thing is “possible,” the statement may refer to two distinct notions: conceptual (mental) possibility and actual possibility in the external world.
Conceptual possibility is simply the absence of knowledge that the thing is impossible. It is nothing more than not knowing of its impossibility; yet not knowing that something is impossible is not the same as knowing that it is possible. Thus, anyone unaware of a thing’s impossibility will, in that limited sense, deem it possible, but this does not amount to knowledge of its possibility.
Whoever argues for a thing’s possibility by saying, “If it were supposed, no contradiction would follow,” without demonstrating that no contradiction whatsoever ensues—as certain scholastic theologians do, such as al-Āmidī and the like—offers nothing more than a bare assertion.