“Why Did Joseph’s Brothers Fail to Recognize Him?”
Genesis 42:8
8 And Joseph knew his brethren, but they knew not him.
An Old Testament CES manual states:
“It had been twenty-two years since the sons of Jacob had last seen Joseph—thirteen years of slavery and prison for Joseph, seven years of plenty, and two years of famine (see Genesis 45:11)—before Jacob’s family was forced to go to Egypt for grain. Joseph was a teenager when his family had last seen him. Now he was a mature, middle-aged man. And, even if Joseph still looked very much as he did when he was younger, who would believe that a brother who was sold as a slave to a caravan of Arabians would have become the second most powerful man in Egypt?”
(Old Testament Student Manual: Genesis–2 Samuel, 3rd ed. [Church Educational System manual, 2003], 96.)