ויראו אחיו כי אותו אהב אביהם מכל אחיו וישנאו אותו ולא יכלו דברו לשלם
When two people do not get along, their inability to maintain an honest discourse which has nothing to do with their disagreement is an indication of their antipathy towards one another. The brothers, regrettably, could not carry on a friendly conversation even about matters unrelated to their discord. On the other hand, as Rashi observes, their incapacity to have a conversation showed their virtue: Their integrity did not allow them to evince a show of friendliness. If they did not feel it – they did not show it. Unfortunately, their refrain from speaking also caused them to avoid rebuking Yosef…