[Shut She'eilat Shlomo 1:481]
Question: When someone drops a plate or glass and it breaks on the floor, there are always those who yell: Mazal Tov, and even clap in joy. Is this proper?
- One should certainly not do this, since it embarrasses someone in public, which is a severe prohibition. The Gemara in Berachot (43b) says that it is better for one to throw himself into a fiery furnace than to embarrass another person in public. Rabbenu Yonah explains that it is better to die than to violate embarrassing another person in public since it has an aspect of murdering another person (commentary on Pirkei Avot 3:15).
- Hillel the Elder already responded to the potential convert who wanted to learn the entire Torah while standing on one foot: What is hateful to you, do not do to your fellow (Shabbat 31a). If I dropped a plate, I certainly would not like someone to yell "Mazal Tov" to me in public, and I should therefore not do so to others.
- If one wishes to respond, he should do a kindness and help him pick up the pieces of the plate. There are three characteristics which distinguish the Jewish People: they are merciful, they are bashful and they are performers of acts of kindness (Yevamot 79a).