Génesis 34:31 Comentario: Rashi, Chizkuni, Sforno & Or HaChaim

הכזונה implies as one unprotected.

?הכזונה יעשה את אחותנו, ,“is he (Sh’chem) to be allowed to treat our sister as if she were a harlot?” Rashi explains the word את in this phrase as emphasising the singular mode as the word אחותנו, occurs several times in the Bible in the plural mode although not spelled in the plural mode with the letter י. [In Aramaic it would then have to be spelled אחותנא instead of אחתנא.

?הכזונה, only a harlot does not have anyone standing up in her defense, avenging violence done to her. יעשה, “shall the people who you are afraid of rising up against us be allowed to get away with such conduct? את אחותנו, who was not a harlot. It is incumbent upon us to avenge her disgrace. Once the inhabitants of the region will understand this they will have no reason to attack us.”

אחותנו The Targum renders it as an accusative — ית אחתנא “our sister”,) so that the meaning is: Should one (be permitted to) make our sister become as a woman who has no-one to protect her (Genesis Rabbah 80:12).