Matthew Poole and continuators on Genesis 42:6

6 And Joseph was the governour over the land, and he it was that sold to all the people of the land: and Josephs brethren came, and bowed down themselves before him , with their faces to the earth.

Either 1. by his Ministers and Commissioners appointed to that end, as men in Scripture and in all Authors are said to do that which others do by their authority and command? Or 2. he himself immediately contracted with the buyers, or at least with such as were forreigners; which he did upon prudential reasons, both because he would not have them to pry into the state of Egypt, ver. 12. and because he would by that opportunity understand the state of other lands and improve that knowledge for his masters service.

Thus unwittingly fulfilling Iosephs dream, Gen. 37. 7.