Avot d'Rabbi Natan, Chapter 14
When Rabban Yohanan ben Zakkai's son died, his disciples came in to comfort him . . . Rabbi Yose entered, sat down before him, and said, "Master, by your leave, may I say something to you?" "Speak," he replied. Rabbi Yose said: "Aaron had two grown sons, both of whom died in one day, yet he was comforted for the loss of them, as it is said, 'And Aaron was silent' [Lev. 10:3]—his silence implies a willingness to be comforted. You, too, must be comforted." Rabban Yohanan said to him, "Is it not enough that I grieve over my own? Do you have to remind me of Aaron's grief?"
We've all been on both sides of this story. Sometimes we find ourselves as the one in mourning or going through a particularly hard time, having to put up with the well-intentioned words of friends and acquaintances that inadvertently rub salt in our wounds; and at other times, we find ourselves trying to offer words of comfort, and speaking banalities that—even as they come out of our mouths—we realize are of no help.
The key here is the verse Rabbi Yose offers from the parashah: "And Aaron was silent." He offers it with an interpretation, that Aaron's silence "implies a willingness to be comforted." All too often, we make assumptions about other people, about what their actions mean, about their inner states, about what they are thinking and feeling. Rabbi Yose here assumes he knows what Aaron's silence meant, and, furthermore, assumes that he knows what will comfort Rabbi Yohanan.
The moral of the midrash is that we should never make assumptions about others. We cannot know what Aaron was feeling when he remained silent after his sons' deaths, we cannot know what Rabban Yohanan ben Zakkai was feeling, and we cannot know what any one of our friends or family feels as they walk through their days and lives. The midrash reminds us not to make assumptions, and to know that our very presence in one another's lives is the best measure of comfort we can offer.