answer:Like this? “The rocks left on top of the tombstone: an unexpected but completely logical feature. In Jewish tradition, small stones are left on top of the grave to honor the dead. Placing a pebble on Gertrude Stein’s grave reclaims her, in a sense, as a Jew, and I was glad to see that people have gotten into the habit of doing this. Proust, happily, gets the same treatment.” Here (Just under half way down)