Genesis 42:15; Genesis 42:16

15 And this is how you will be tested: As surely as Pharaoh lives, you will not leave this place unless your youngest brother comes here.

16 Send one of your number to get your brother; the rest of you will be kept in prison, so that your words may be tested to see if you are telling the truth. If you are not, then as surely as Pharaoh lives, you are spies!”