Musar do Rodzaju 42:21

איש אל אחיו אבל אשמים אנחנו . They confessed their sin and went into the details as is necessary in order for a confession to be legally valid. Even according to the opinion that one does not have to confess to all details it is certainly better if one does so. In this instance the details included watching Joseph's anguish, listening to his entreaties, and failing to respond. When man confesses before his Maker, he must weep, entreat, and mourn. When the brothers said אבל אשמים אנחנו, the first word should be read as Eyvel.

Moreover, Joseph had already heard the brothers express remorse over the way they had treated Joseph (42, 21) We have found another Midrash according to which the brothers tried to kill Joseph when he revealed himself, but that an angel intervened and scattered them. The assumption underlying that statement seems to be that the brothers felt so ashamed that their very shame prompted them to do away with its cause. Psychologically, this seems strange indeed! Remorse and repentance are traditionally feelings triggered by shame. Why, in this case, should these feelings of shame have triggered the opposite reaction? We have ample proof from scripture that shame leads to repentance and forgiveness of one's sins, viz. Ezra 9,6: "O my G–d, I am too ashamed and mortified to lift my face to You, O my G–d, etc." We are told in Berachot 12b, that whoever commits a sin and is ashamed of that sin will have his sins forgiven. How then could feelings of shame have triggered the brothers' desire to kill Joseph?