After their lunch with Zaphnathpaaneah, for that was Joseph's Egyptian name, the sons of Jacob found their sacks filled to full quickly and they were sent on their way with all that they could handle. That was easy, right? Well, not so fast. Brother Joe set them up with one last test. He had his personal cup placed in Benjamin's sack.
After the men had gone only a short distance, Joseph's steward caught them and accused them strongly of stealing his master's cup. They were adamant. They had returned the money that had been mysteriously present in their sacks before. Was that the behavior of thieves? They were so confident of their innocence that they even offered the life of whoever was guilty. So, when the steward searched the sacks, the men were utterly horrified when Benjamin was the one who held the cup.
When they stood before Joseph again, he tested their sincerity strongly. He offered to let them all go home while Benjamin was retained. They refused. Clearly something had changed since the day that they had frivolously and casually sold Joseph into slavery.
Judah stepped up to the plate. Without realizing that he was doing it, Judah gave the most persuasive argument possible to Joseph as he implored him to spare them. He told "Zaphnathpaaneah" that if he kept Benjamin, the loss would kill their father. Then he added that he would willingly stay in Benjamin’s place.
Things had definitely changed. The brothers had changed. God was gracious enough to give them a second chance... and they passed the test!