Manhattan - (Holy Smoke!): The spat goes back to the band's Giza Sound and Light Theater gig of September 14/16 1978 during a total lunar eclipse.
Documents filed before the Lower Manhattan District Court say Jerry Garcia found some papyrii stuffed down the Sphinx's throat.
These turned out to be relics from the ancient Jewish fortress of Masada mocking first century Roman polymath Pliny the Elder (don't ask!).
A Garcia/Hunter song about the spat is now at the center of a plagiarism dispute brought about by Scrolls scholars.
Litigants allege some of the lyrics of the band's subsequent Shaikh Down Street album use The Nubian Youth Choir's copywritten material.
This was handed down to them in oral tradition by the much maligned Pliny.
But attorneys acting for Garcia's estate say Pliny the Elder was off his tree and plagiarised much of the Masada texts from Garcia's forebears.
A motion to take the judge and jury to the ancient Egyptian site to this year's Winter's Solstice - when another total lunar eclipse occurs - is being considered by the court.
Phil Lesh is 69.