What did Yosef mean when he countered, "Chalilah Li... "?
Ramban #1: He argued that their contention that a group of ten men... ten partners... are all guilty 1 is only applicable there where they planned the theft together that one of them would steal the article on behalf of all of them, but not where the thief acted on his own.
Ramban #2 (explaining Rashi): 'It is profane for me to sentence you more harshly than the manager of my household, who acquitted you completely.'
Seforno: He countered that he was not Hashem's Shali'ach to punish them for their former sins, and that he was only prepared to punish the one who sinned against him. Ohr ha'Chayim - I will punish you only for what is revealed.
Beis ha'Levi: Yehudah said that from all the occurrences, it is evident that the man over your house seeks a pretext against us. Yosef said, Heaven forbid that I should increase suspicion, not against you or my overseer. Only the one with whom it was found will be my slave.
Malbim: Even though I can say this and suspect all of you, surely I will not punish based on suspicion!
If the brothers would have accepted Yosef's suggestion, what would he have done?
Oznayim la'Torah: No doubt, Yosef would still have revealed himself to his brothers, and then to invite his father and Binyamin to join him. Only he would have been afraid of his brothers, who hated the children of Rachel, one of whom they sold, the other, handed over as a slave. 1
Oznayim la'Torah: But now that he saw how they were Moser Nefesh on behalf of Binyamin, he revealed himself to them with brotherly love and invited them all to come and join him in Egypt, in keeping with G-d's will - to begin Galus Egypt.