Genesis 42:21

We are verily guilty. As they realized that this lord of Egypt would not punish or slay them upon mere suspicion, but judge them justly, their consciences began to speak. How differently they had acted toward Joseph! The ruler of all Egypt had compassion on their families, who suffered hunger in Canaan, whereas they had intended to leave their brother in the pit to starve. As these and similar thoughts passed through their minds, they were led to an acknowledgment of their guilt. Their own misfortune brought back to them the anguish of their brother. Reuben reminded them of how he had warned them, unsuccessfully, not to sin against the boy, and now they were receiving a just reward for their coldness toward him. Thus they accused themselves in Joseph’s presence, without realizing that he understood every word.