Joseph was using an interpreter to talk to his brothers. So the brothers did not know that Joseph understood their language. But Joseph heard and understood everything they said.
Then Reuben said to them, “I told you not to do anything bad to that boy. But you refused to listen to me. So now we are being punished for his death.”
{Their words made Joseph very sad.} So Joseph left them and cried. After a short time, Joseph went back to them. He took Simeon, one of the brothers, and tied him while the other brothers watched.