Commento su Genesi 42:12

כי ערות הארץ באתם לראות BUT TO SEE THE NAKEDNESS OF THE LAND YE ARE COME — I still insist that you are spies, for what you have just said bears this out for you have entered by ten different gates of the city; why did you not all enter by the same gate if you are really brothers and travelled together? (Genesis Rabbah 91:6).

ויאמר אליהם לא, כי ערות הארץ באתם לראות, if it were as you said, how could you not even leave one of you at home to attend to the needs of your father? Joseph said all this in order to find out if his full brother Binyamin was alive. As a result of his probing they elaborated that in fact they were a total of twelve brothers, one, the youngest having remained at home and one having been lost. They did not know his whereabouts or if he was even alive. We know that there were several questions and answers as when the brothers returned home and their father was reprimanding them for volunteering uncalled for information about their family status, they replied that the “man” had kept asking more and more questions. (compare 43,7)

לא. It is simply not true that you are brothers.