Komentarz do Rodzaju 42:5

בתוך הבאים AMONG THOSE THAT CAME — They hid themselves in the crowd that people should not recognize them, for their father had bidden them not to show themselves all at one entrance to the city but that each should enter by a different gate in order that the evil eye should not have power over them (i.e. that they should not attract the envious attention of the people) for they were all handsome and stalwart men (Midrash Tanchuma 1.:10:6).

בתוך הבאים, people traveled together in large groups to afford themselves protection against highway robbers. At that time there were more than the usual amount of these. They would rob both the money carried to buy food and the food itself

ויבאו בני ישראל…כי היה רעב, The children of Israel arrived…for there was a famine in the land of Canaan. The fact that there was a famine had to be repeated. This is to explain why the Torah first wrote בתוך הבאים. You should not ask where these הבאים have been mentioned previously so that the Torah could describe the brothers as "being amongst them." Once we are told that there was a famine in Canaan it becomes obvious that many other people from Canaan must have been going to Egypt to buy grain there.

בתוך הבאים, they did not appear different although they were Hebrews. Seeing that it was a time of danger, i.e. famine, they mingled freely with all the other people traveling to Egypt for the same purpose.

Hier treten sie zum erstenmale als בני ישראל auf. Es war dies auch ein Moment von keiner kleinen Entscheidung. Die ganze Zukunft trug er in seinem Schoße. Und sie kamen בתוך הבאי׳. Es ahnte ihnen nichts von dem Folgenschweren dieses ganzen. —

בתוך הבאים, “they intermingled with others going to Egypt for the same purpose, disguising themselves so as not to draw attention to themselves as they had been commanded to do by their father, when he had said: למה תתראו, “why do you draw attention to yourselves?”

The Torah also wanted to indicate that the brothers devised a clever scheme to disguise themselves "among the other travellers." They created the impression that they were in Egypt for the same purpose as all the other travellers from Canaan, whereas in reality they were searching for Joseph. In other words: the brothers' disguise was to appear as shoppers for grain. This ought to have been an easy way to camouflage their real purpose because of the famine in the land of Canaan.