Genesis 44:15
And Joseph said unto them, What deed is this that ye have done? wot ye not that such a man as I can certainly divine?
And Joseph said unto them, What deed is this ye have done?.... An action so wicked, base, and ungrateful, attended with such aggravated circumstances, that it can scarcely be said how bad a one it is, and may be well wondered at, that men who had received such favours could ever be guilty of; this he said, putting on a stern countenance, and seemingly in great anger and wrath:
wot ye not that such a man as I can certainly divine? either that he could divine himself, though not by the cup, of which here no mention is made, but in some other way used by the Egyptians; or that he had diviners with him, as Aben Ezra, with whom he could consult, to find out the person that took the cup; or surely they must needs think that such a man as he, who had such great knowledge of things, natural and political, and whose name was Zaphnathpaaneah, a revealer of secrets, would be able to search into and find out an affair of this kind;
See Gill on "Genesis 41:45"; and they might well conclude, that a man so sagacious and penetrating would easily conjecture who were the persons that took away his cup, even the strangers that had dined with him so lately, and therefore could never expect to go off with it.