We may well wonder that Joseph, during the twenty years he had been in Egypt, especially during the last seven years that he had been in power there, never sent to his father to acquaint him with his circumstances; nay, it is strange that he, who so oft went through all the land of Egypt, never made a step to Canaan, to visit his aged father. When he was in the borders of Egypt that lay next to Canaan, perhaps it would not have been above three or four days' journey for him in his chariot. It is a probable conjecture, that his whole management of himself in this affair was by special direction from Heaven, that the purpose of God, concerning Jacob and his family, might be accomplished. When Joseph's brethren came, he knew them by many a good token, but they knew not him, little thinking to find him there.
Related Commentaries of Genesis 42:7
Genesis 42:7
7 And Joseph saw his brethren, and he knew them, but made himself strange unto them, and spake roughlya unto them; and he said unto them, Whence come ye? And they said, From the land of Canaan to buy food.