Genesis 42:33-34

And the man, the lord of the land, said unto us, Hereby shall I know that ye are true men: leave one of your brethren with me, and take grain for the famine of your houses, and go your way; and bring your youngest brother unto me: then shall I know that ye are no spies, but that ye are true men: so will I deliver you your brother, and ye shall traffic in the land.