John Calvin Commentary Genesis 42:6

"And Joseph was the governor over the land; he it was that sold to all the people of the land. And Joseph`s brethren came, and bowed down themselves to him with their faces to the earth." — Genesis 42:6 (ASV)

And Joseph was the governor over the land. Moses connects Joseph's honor with his fidelity and diligence. For although he possessed supreme authority, he nevertheless submitted to every possible laborious service, just as if he had been a hired servant.

From this example we must learn that as anyone excels in honor, he is bound to be more fully occupied with his duties; but those who desire to combine leisure with dignity utterly pervert the sacred order of God.

Moreover, let it be understood that the grain was sold by Joseph. It was not that he measured it out with his own hands or received the money for it himself (since it was offered for sale in many parts of the kingdom, and he could scarcely have attended to even one storehouse); rather, all the stores were under his power.