Genesis 42:15-22

15hereby ye shall be proved: by the life of Pharaoh ye shall not go forth hence, except your youngest brother come hither. 16Send one of you, and let him fetch your brother, and ye shall be bound, that your words may be proved, whether there be truth in you: or else by the life of Pharaoh surely ye are spies. 17And he put them all together into ward three days.

18And Joseph said unto them the third day, This do, and live; for I fear God: 19if ye be true men, let one of your brethren be bound in your prison-house; but go ye, carry grain for the famine of your houses: 20and bring your youngest brother unto me; so shall your words be verified, and ye shall not die. And they did so. 21And they said one to another, We are verily guilty concerning our brother, in that we saw the distress of his soul, when he besought us, and we would not hear; therefore is this distress come upon us. 22And Reuben answered them, saying, Spake I not unto you, saying, Do not sin against the child; and ye would not hear? therefore also, behold, his blood is required.