Genesis 42:23 in the King James Version
And they knew not that Joseph understood them; for he spake unto them by an interpreter.
Context
22 Reuben answered them, saying, “Didn’t I tell you, saying, ‘Don’t sin against the child,’ and you wouldn’t listen? Therefore also, behold, his blood is required.”
23 They didn’t know that Joseph understood them; for there was an interpreter between them.
24 He turned himself away from them, and wept. Then he returned to them, and spoke to them, and took Simeon from among them, and bound him before their eyes.