There's a rather curious religious custom described in the Mishnah, and I was hoping someone who knows Greek and/or Roman religious practices could shed some light on it.
There's a discussion about non-Jewish forms of worship that, to the uninformed observer, would look like contempt, rather than worship. One example given is "throwing a stone to Merkulis" (Mercury?). Is throwing rocks at a representation of a diety a documented religious practice in the Mediterranean world from this period?
It probably refers to the herma or herm. It's a stone pillar with a bust of a bearded man on top and male genitals on one side ([example] (https://www.getty.edu/art/collection/objects/8640/attributed-to-the-workshop-of-boethos-of-kalchedon-herm-of-dionysos-greek-about-200-100-bc/) ) These started as piles of stones on crossroads and boundaries that were considered sacred to Hermes. People passing by would pay respects by throwing a stone at a pile.
I don't really know much more about them, except that they are referenced by Thucydides in [History of the Peloponnesian War] (http://www.perseus.tufts.edu/hopper/text?doc=Thuc.%206.27.1&lang=original) , but it's a good place to start looking.