Rabbi Rabbi Shimon ben Elazar said “Do not try to placate your friends at the height of their anger; do not attempt to comfort them in the first shock of bereavement; do not question their sincerity at the moment when they make a solemn promise; do not be overeager to visit them in the hour of their disgrace.”
From “Chapters of the Fathers” in Gates of Prayer, Chaim Stern, ed. (New York: Central Conference of American Rabbis, 1975), 24.