But here he is, photographed this weekend at Los Angeles synagogue, doing just that:
The 39-year-old NBA star, it turns out, is a close family friend of Jeffrey Feinberg, a hedge fun manager and the father of Mike Feinberg, the 13-year-old Bar Mitzvah boy.
Feinberg, the father, spent years working as an executive for George Soros's hedge fund company before spinning off his own firm.
He's a huge NBA fan, and even reportedly considered buying a stake in the Brooklyn Nets in 2009. His wife, Mike's mom Stacey, is the daughter of legendary sports agent Bob Woolf, who represented Larry Bird, Doug Flutie and others.
Friends and family of the Bar Mitzvah are often asked to assist in the service as an honor, sometimes even being called for aliyah, or reading from the Torah. Non-Jewish friends and family can't do quite that much, but they are sometimes asked to help re-dress the Torah scrolls in their protective covering and decorative ornaments, or hold the scrolls until it is time to return them to the ark (like Nash appears to be doing).