Комментарий к Берешит 44:12

בגדול החל AT THE ELDEST HE BEGAN — so that they should not perceive that he knew where it was (Genesis Rabbah 92.8).

ויחפש, בגדול החל, in order that they should not suspect him of having planted the goblet in Binyamin’s sack, he made a show of starting to search the oldest, etc. He knew their respective rank in seniority from the way Joseph had seated them at the meal.

בגדול החל, “he began by searching the sack of the oldest.” He did this in order that they should not realize the goblet had been a plant.

וימצא הגביע, “the goblet was found;” as far as the money found in the bags also is concerned this was not part of the accusation of thievery, as it could not be proven that it was not excess money that the brothers had had with them not knowing the price of their purchase in advance.

וימצא הגביע באמתחת בנימין, “the goblet was discovered in the feeding bag of Binyamin.” His other brothers began to shame him by calling him “thief,” and other disparaging names, referring to his mother who had stolen the teraphim of her father Lavan (Genesis 31,19). They also struck him on his shoulders. Seeing that Binyamin had been unjustly suspected by his brothers of being a thief he was compensated by G’d in that the Holy Temple was erected on his tribal territory. This is what Moses meant in his blessing of Binyamin (Deut. 33,12) when he said ובין כתיפיו ישכון that G’d’s Presence would reside between “the shoulders of Binyamin.” He also became the ancestor of Mordechai, who had torn his garments in lament for the fate that threatened the Jewish people at the hands of Haman (Esther 4,1). The brothers deserved to have to rend their garments (verse 13) seeing they had caused their father to rend his garments (Genesis 37,34) when he mourned the presumed death of Joseph. Everything that befell the brothers was in the nature of the punishment fitting the crime.
Menashe, Joseph’s firstborn, acted as his father’s emissary in all these matters as the Torah describes him as “in charge of Joseph’s palace” (verse 1) and Targum Yonatan writes that Menashe was the individual the Torah referred to. Seeing that Menashe allowed himself to become part of this deception and caused the brothers to rend their clothing in frustration, his tribal territory was rent, i.e. was divided, part of it being on the East Bank of the river Jordan.