Now Joseph was the governor of the land, the person who sold grain to all its people. So when Joseph’s brothers arrived, they bowed down to him with their faces to the ground. As soon as Joseph saw his brothers, he recognized them, but he pretended to be a stranger and spoke harshly to them. “Where do you come from?” he asked.
”From the land of Canaan,” they replied, “to buy food.”
Although Joseph recognized his brothers, they did not recognize him.  Genesis 42:6-8
Joseph was the one whose brothers were jealous of him, threw him into a pit and sold him into slavery, telling their father Jacob that Joseph was killed by a wild animal. God used Joseph to rise up in power in Egypt, fulfilling a dream Joseph had, that one day he would become a ruler and his brothers would bow to him. During a famine, the brothers came to the ruler of Egypt (Joseph) asking for food. They did not recognize him on the throne. Does that seem unusual? There are a few possible reasons why.

• MATURITY: Joseph has been away for over ten years. He departed them as a late teen and now is in his late twenties. Joseph acted more like a man.  Maybe his voice had changed from teenager to adult male.
• APPEARANCE: Joseph lived through slavery, prison, then experienced the finest in Egyptian lifestyle, now dressed in the best clothes, after sitting in the Egyptian sun. Egyptians were also clean shaven (41:14) while shepherds looked scraggily.  Joseph's looks had changed.
• EXPECTATION: They were not expecting to see Joseph at all. They were convinced he was dead.
• DISTANCE: As a ruler, the subjects kept their distance from the one in charge. You didn’t walk up to a ruler and shake hands. From fifteen feet away, he couldn’t get a good look at his face.
• PREJUDICE: Genesis 43:32 said that Egyptians thought that eating with Hebrews was detestable.  Because of this kind of prejudice, there was a separation between the cultures.
• LANGUAGE: Joseph spoke Egyptian and used a translator (42:23).  Maybe he had acquired an accent, so he didn’t sound like the old Joseph.