Genesis 42
33 Ref 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;
34 Ref 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.