What does Genesis 42:15 mean?
In the eyes of his brothers, Joseph (Genesis 41:41–45) is a powerful Egyptian official. They don't recognize him as the brother they once jealously sold into slavery (Genesis 37:28). Their attempt to buy food from him (Genesis 41:1–5) has taken an absurd and threatening turn. For no reason they can see, Joseph has accused them of being spies sent to find Egypt's military weaknesses (Genesis 41:6–14). This is partly to maintain Joseph's secret, but it also serves to intimidate them into giving more information.In attempting to show they are honest, normal men, the brothers have revealed that they have another, younger brother back home. Still speaking as an Egyptian official, Joseph has pounced on that information (Genesis 43:6) as a test of their truthfulness. Unless they can show him their brother, he will not believe them and not let them go home (Genesis 42:16–17).