Genesis 42:16
“Send one of you, and let him get your brother, and you shall be bound, that your words may be tested, whether there is truth in you, or else by the life of Pharaoh surely you are spies.””
What does Genesis 42:16 mean?
Joseph has accused his brothers of being spies, and now he's laying down a test to prove their story. He's saying: one of you stays here in prison while the rest of you go home and bring back your youngest brother, Benjamin. Only then will he know they're telling the truth. Joseph isn't being cruel for its own sake; he's protecting Egypt from actual threats, and he's also testing whether his brothers have changed since the day they sold him into slavery years before. The mention of Pharaoh's life was simply how people swore oaths back then, like saying "as surely as the king lives." What matters here is that Joseph is trying to verify a story that sounds suspicious to him, and he's using the only leverage he has: their freedom, their food, and their family.