פּירוש אויף בראשית 42:6

וישתחוו לו אפים means THEY PROSTRATED THEMSELVES ON THEIR FACES— Similarly wherever various forms of this verb (שחה) in the Hithpael occur it implies stretching out the hands and feet when a person casts himself on the ground in the act of prostration (Megillah 22b).

HE IT WAS THAT SOLD GRAIN TO ALL THE PEOPLE OF THE LAND. Now it is not befitting a ruler of a land, second in rank to the king of Egypt, that he sell everyone a se’ah [a dry measure] or a half thereof of grain. It was for this reason that our Rabbis were impelled to say¹²¹Bereshith Rabbah 91:6. that Joseph had ordered at that time that all storehouses except one be closed so that he would be sure to meet his brothers.
In line with the literal interpretation of the verse it is possible that the people from all lands came before him, and he would question and investigate them, and then command the officers, “Sell so much food of this — and that — kind to the people of that city.” Thus it was necessary for the children of Jacob to come before him among those who came from the land of Canaan, that he could issue an order concerning them, specifying how much grain should be sold to their land, since they were the first to come from the land of Canaan¹²²See further, at the end of Verse 9, where Ramban establishes the fact that the brothers were the first to come from the land of Canaan to buy grains, thus offering Joseph the opportunity to charge them as spies. and they came before him for the sake of all.

ויוסף הוא השליט, the brothers had to appear before him personally as he was the seller, i.e. he authorised who could buy and how much. הוא המשביר. The term is only used transitively, someone who sells somebody else’s property to a third party. He gave instructions to his agents to sell. Initially, all potential purchasers had to be examined by Joseph personally. Although, no doubt this was a tedious procedure, Joseph had issued these instructions to make sure he would spot his brothers when they would arrive, as he was sure they must. As a result he would be able to confront his brothers.