Genesis 42:9-17

9And Joseph remembered the dreams that he had dreamt of them; and he said to them, Ye are spies: to see the exposed places of the land ye are come.

10And they said to him, No, my lord; but to buy food are thy servants come.

11We are all one man's sons; we are honest: thy servants are not spies.

12And he said to them, No; but to see the exposed places of the land are ye come.

13And they said, Thy servants were twelve brethren, sons of one man, in the land of Canaan; and behold, the youngest is this day with our father, and one is not.

14And Joseph said to them, That is it that I have spoken to you, saying, Ye are spies.

15By this ye shall be put to the proof: as Pharaoh lives, ye shall not go forth hence, unless your youngest brother come hither!

16Send one of you, that he may fetch your brother, but ye shall be imprisoned, and your words shall be put to the proof, whether the truth is in you; and if not, as Pharaoh lives, ye are spies.

17And he put them in custody three days.