What does Genesis 42:11 mean?

Joseph has accused his ten older brothers of being spies. He declares that they have come to Egypt to spy for a foreign power. They are trying to defend themselves, insisting they have come only to buy food in the famine (Genesis 42:6–10). Their language is the common style of that era: politely referring to themselves as the servants of the other. The situation is unique, however, in that Joseph alone has the power to act on that accusation (Genesis 41:44). The brothers do not realize that the Egyptian governor, whom they know as Zaphenath-paneah (Genesis 41:45), is the brother they sold into slavery twenty years ago (Genesis 37:28). Joseph's intent is not revenge, but to test his family; the end goal is to bring them all safely into Egypt (Genesis 47:11–12).

Since the ten men (Genesis 41:1–5) don't know this is their brother, they reveal another detail: They are all sons of the same man (Genesis 35:23–26). Joseph knows this, of course, but it is information he can use to learn more about them. They conclude by declaring that they are honest men who have never been spies. This might have been another reason for Joseph's harsh approach: coercing his brothers to give him more longed-for information about his family.