No More Sorrow
The correct wording is "May God comfort you among all of the mourners of Zion and Jerusalem." Many people add "May you know no more sorrow".
I'm not entirely sure how to interpret the last sentiment. I first thought that it meant that everyone in the entire world all should die soon and at the same time. Then I thought, maybe it means that I should die first.
Either way, I'm not sure it's a comfort.
Today I thought of a third possibility: I should suffer brain damage so that I can no longer experience sorrow.
Who's Comforting Whom?
The ideal comforter responds to your conversation, helps you talk about the departed, or tells you their fond memories of the departed. More than half of my visitors have been ideal. Some have been, uh, less than ideal.
One visitor type who is neither ideal nor specifically problematic is the one who doesn't know how to talk or respond, but simply stares at you. Luckily, other visitors have arrived whenever I had one of those.
How Long to Stay
I was told that one stays until one finds him/herself to be the longest visitor remaining and then new visitors arrive, unless the bereaved specifically indicates that you should stay longer. I now realize that this is because you will already have heard all the stories told by the bereaved, who is starting in on them for the nth time.
Another good time to leave is when the conversation lags for the fourth time and the bereaved is tapping his fingers on his chair and staring pointedly at you.
Words About My Father
A few words about my father, as painted by the ideal visitors:
People set their watches to the times my father arrived at shul for the past few decades. He rarely missed a davening, unless he was in the hospital or away, even during the over two years that he had liver cancer. He went up for an aliyah to the torah on the Thursday before he passed away.
Even the children in his community knew him, and he always had a smile for them. They were inspired by his thrice daily trek to and from shul. One ten year old boy wrote out how he felt about my father so that he could read it to us at the shiva.
My father helped found the early minyan in West Hempstead where I grew up. When he came to Beit Shemesh there was no synagogue yet organized, so he and my mom simply hosted the synagogue in their house for four years. One of the three minyans that they have in the shul on shabbat morning is, even now, referred to as the Berlinger minyan.
He spent the last 7 or 8 years at kollel every morning, and he loved it. He would never let anything go by; he had to understand it, and it had to make sense to him, or the shiur could not continue. He learned in chavruta nearly every shabbat afternoon.
My father grew up religious and stayed religious. He didn't always know what to do, but he always wanted it done properly. Whatever was proper, that was what had to be done, no excuses.
He was, in a word, determined.