What Does Genesis 42:23 Mean?

They did not know that Joseph understood them, for there was an interpreter between them. The crucial detail of verse 23 is the interpreter: the official Egyptian translator who mediated all communication between Joseph and his brothers. The brothers believed they were speaking privately among themselves in a language the Egyptian official could not understand. The conversation of verses 21 to 22: the guilt confession, the blood reckoning, the "I told you": was spoken in the confidence that the official could not hear it. But Joseph heard every word.

The interpreter's presence in all the previous exchanges means that Joseph's official Egyptian speech was rendered into the brothers' language (Canaanite Hebrew) for them, while their private words to each other were spoken in Joseph's native language that the official: Joseph himself: understood perfectly without the interpreter's help. The dramatic irony is complete: the brothers confessed their guilt in their native tongue to each other, assuming privacy, before the one person who needed to hear that confession and who understood every word of it. The interpreter is the structural mechanism that makes this possible.

Joseph hearing the brothers' guilt confession is the chapter's emotional turning point. He has been "speaking roughly" (v.7), maintaining an official persona, conducting a test. Now he hears his brothers say "we saw the distress of his soul, when he begged us and we did not listen." He hears Reuben say "a reckoning for his blood." He is hearing the acknowledgment of his brothers' guilt: finally, twenty-two years later: in their own words, assuming no one who matters can hear them. The acknowledgment is real because it is not offered for his benefit; it is said to each other in private. And it leads directly to verse 24.