Genesis 42:9
And Joseph remembered the dreams which he dreamed of them, and said unto them, Ye are spies; to see the nakedness of the land ye are come. And Joseph remembered the dreams which he dreamed of them, and said unto them, Ye are spies; to see the nakedness of the land ye are come.
The brothers arrived in Egypt among the throng of purchasers seeking grain, and they prostrated themselves before the governor with their faces to the ground. He recognized them at once though they failed to recognize him, so he carried himself as a stranger toward them and addressed them harshly, demanding to know where they had come from. When they replied that they had come from the land of Canaan to buy food, the encounter stood exactly as described.
As they bowed he recalled the dreams in which they bowed down to him, now fulfilled before his eyes. He charged them with being spies who had come to look upon the exposed and defenseless parts of the country. The accusation was not made from genuine belief but as a means to prove them and lay open their character.
By that proving he aimed to gain knowledge of his household, to draw out information concerning them, and especially to learn whether his father and Benjamin were still living. When they protested that they had come for no purpose but to buy food, he pressed the charge of spying a second time, desiring to see whether the haughty temper they had shown in former days still remained in them. Under the humbling weight of trouble they answered his suspicion with sorrow rather than with anger. He then professed to disbelieve their statement that they were twelve brothers, sons of one man, with the youngest still with their father and one lost, and he required proof by holding them in confinement while one of them went to fetch the youngest, declaring that refusal would stand as evidence that they were spies.