Genesis 42:33-34

Then the man, the governor of Egypt, demanded, ‘By this test, I will discern if you are honest men: Leave one of your brothers with me, take the grain you need for your families, and be on your way. Return to me with your youngest brother, then I’ll know you are not spies, but men of integrity. Then I’ll release your brother back to you, and you’ll be free to trade in the land.’ ”