John Gill Commentary Genesis 42:8

"And Joseph knew his brethren, but they knew not him." — Genesis 42:8 (ASV)

And Joseph knew his brethren, but they knew not him . It being about twenty two years since they saw him, and then he was young, and his beard not grown, as now it was; and besides, he was clothed as a prince, and spoke the Egyptian language; and being in such great grandeur and splendour, and in such power and authority, and having such a retinue attending him, they never once thought of him, whom they supposed might be dead, having never heard of him all this time; or, however, it could not come into their minds, that he whom they sold for a slave could ever be governor of the land of Egypt.