What does Genesis 42:12 mean?
In most circumstances, false accusations could lead to an innocent person being jailed or executed. Joseph has accused his ten older brothers of spying (Genesis 42:9–11), a crime of which they are innocent (Genesis 42:1–5). As it happens, Joseph is now the governor of all Egypt (Genesis 42:6), so there is no actual danger. Of course, his brothers do not know this, because they don't recognize him as the boy sold into slavery some twenty years in the past (Genesis 37:28).They have flatly denied his charge, revealing a little more of their story. He refuses their defense, however, and makes the accusation again. Here, Joseph repeats his challenge: that these men have come to Egypt to find military weaknesses to report back to some foreign power.
It's difficult to know Joseph's complete motivation in this exchange. He knows, of course, that his brothers are not spies. This does not seem to be revenge on them for what they did to him all those years ago, else he would likely have revealed himself and had them punished. At least part of the motive seems to be to maintain his secret (Genesis 42:23–24; 43:30; 45:1–5). This makes it likely Joseph is simply using an interrogation technique—intimidation—to wring out more information about his family.
Genesis 42:1–17 contains the unlikeliest of reunions: that between Joseph and his ten oldest brothers (Genesis 37:28). They have been sent by Jacob to Egypt to buy grain during a terrible famine (Genesis 41:53–54). They don't recognize their brother, now an Egyptian ruler. Joseph knows them but keeps the secret; he responds harshly to avoid breaking the illusion. He then puts them in prison for three days, saying they might be spies. All the while, he has a plan in mind.
Genesis 42 describes the moment Joseph sees his brothers for the first time since they sold him into slavery over 20 years earlier. They have come to Egypt to buy grain, and they do not recognize him. He keeps his secret, speaking roughly to them and hinting they may be spies. He allows them to leave only if they promise to return with their youngest brother Benjamin. He keeps Simeon as collateral but sends them off with full sacks of grain for their family. He also secretly returns their money, something they are terrified to discover on the way home. Back in Canaan, Jacob responds to this terrible news with bitterness and vindictive blame.