Every year, in late summer, the scorching hillsides of Calabria, Italy, are the site of an unusual tradition: rabbis crawling around the base of citrus trees, examining their roots and weighing their fruit. They’re here to find the perfect etrog — a kind of citron that is the ceremonial centerpiece for the annual feast of Sukkot. John Last went with a group of rabbis on the annual inspection tour and reports on the business and personal relationships that have come from this tradition.