창세기 50:15의 주석

ויראו אחי יוסף כי מת אביהם AND WHEN JOSEPH S BRETHREN SAW THAT THEIR FATHER WAS DEAD — What is the meaning of “and they saw”? They could perceive that he was dead through the conduct of Joseph. Previously they used to dine at Joseph’s table and he used to receive them with open arms out of respect to his father; after Jacob’s death, however, he no longer treated them in a friendly manner (Tanchuma Yashan 2:1:2; Genesis Rabbah 100:8).

לו ישטמנו יוסף, "perhaps Joseph will hate us, etc." In this instance the word לו means "perhaps," though there is no other such instance in the Torah where the word לו is used in that sense. We need to understand why the Torah uses the word לו here in a sense which is the opposite of its regular meaning. Although it is quite impossible to mistake the meaning of this word in our context, why did the Torah not use such words as פן, or אולי if the intention was to describe the brothers as saying "perhaps?"

לו ישטמנו, “supposing Joseph were to turn hostile against us? They hoped that Joseph’s hostility against them would be restricted to his heart and would not manifest itself openly. [this interpretation assumes that the word לו is a wishful expression as it is elsewhere. Ed.]