Ge 42:8 So Joseph recognized his brothers, but they did not recognize him.
Joseph had plainly told his brothers that they would someday bow down to him. His brothers knew that Joseph was in Egypt. They knew that they had sinned in selling Joseph as a slave. And they knew that God had promised great things to Joseph.
Yet when they went to Egypt, met a great leader, bowed down to him, and received punishment for their sins, it didn't even occur to them that this was their brother! They even spoke in Hebrew in his presence, assuming that he wouldn't understand them.
Joseph's ten older brothers had been taught properly. Yet, they lacked the wisdom and the knowledge to recognize their brother. Why?