Genesis 42:16-19

16One of you must go to bring your brother here. I will keep you others in prison. In that way I will know if what you said is true. If your youngest brother does not come, then I will certainly know that you are enemies!’

17Then Joseph put his brothers in prison for three days.

18On the third day Joseph said to them, ‘Do what I say. Then you will stay alive, because I respect God.

19If you are honest men, let one of your brothers stay here in prison. The other brothers can go back to Canaan. You may take food back with you, because your families are hungry.