Question: Why do some people turn the shovel upside-down at a Jewish burial?
Answer: Thanks for your question about turning the shovel upside-down at a funeral.
Not everything that Jews do in their religious rituals is a matter of Jewish law. A lot of the behaviors that we assume are required aspects of Jewish ritual -- eating braided bread on Shabbat, for example -- are actually matters of custom, not law. Different Jewish communities have different customs, or minhagim, for different rituals.
That is why if you spend Shabbat with a Yemenite Jewish family, you may not see a braided challah on the table. That is a minhag that originated in Europe; not in the Middle East.
There are many different minhagim for Jewish funerals. Some communities insist that the shovel used to place earth in the grave must be held upside-down as a sign of reluctance to fulfill the mitzvah of burying the dead. Some say that just the first shovel of earth should be done in this way. Some say each person puts in three shovelfulls of earth, some say more, some say fewer. None of these choices are a matter of Jewish law.
The important thing is not that you insist on just one way of doing things. Customs can have deep meaning for a community, or they can just be a way for one person to assert that he is right and everyone else is wrong. Each person, family and community should follow the customs that are meaningful for them.
Rabbi Jeffrey W. Goldwasser