An inscribed tablet of the Ten Commandments — claimed to be the world’s oldest known extant example — will go on auction December 18 with expectations of garnering as much as $2 million. The esteemed auction house Sotheby’s is facilitating the sale of what it says is an approximately 1,500-year-old tablet, which it describes as “the only complete tablet of the Ten Commandments still extant from this early era.”

Sotheby’s New York began displaying the marble tablet on December 5. It will be auctioned at 10 a.m. on Wednesday, December 18.

Dating to the time of the Eastern Roman Empire between A.D. 300-800, the 115-pound, two-foot-tall tablet was unearthed in Israel during railway excavations in 1913. Sotheby’s notes that for 30 years before its significance was discovered, it served as paving stone in a local home. A scholar bought the tablet in 1943. It is known as the Yavne Tablet for the Israeli city where it was rediscovered.

Some experts attribute the tablet’s creation to Israelite Samaritans, who consider themselves culturally and ethnically distinct from Jews. While it includes 10 commandments, only nine of them come from the traditional Ten Commandment lists in the books of Exodus or Deuteronomy. Not included is the commandment “Thou shalt not take the name of the Lord in vain.” Instead, it includes a commandment to worship on Mount Gerizim, “a holy site specific to the Samaritans,” according to Sotheby’s description.

Deuteronomy 11:29 names Mount Gerizim as a site for proclaiming blessings. The site is in today’s West Bank.

The tablet includes chiseled Paleo-Hebrew script, with each line containing 11 to 15 characters, with some of the characters “effaced and re-inscribed,” according to the auction house.

In a statement on Sotheby’s website, Richard Austin, Sotheby’s global head of books and manuscripts, called the artifact a “remarkable tablet is not only a vastly important historic artifact, but a tangible link to the beliefs that helped shape Western civilization.”

“To encounter this shared piece of cultural heritage is to journey through millennia and connect with cultures and faiths told through one of humanity’s earliest and most enduring moral codes,” he said.

However, some experts have expressed concern over the provenance of the artifact — and whether its authenticity can be firmly established — as it was not uncovered in an archeological dig.

“The problem is that we have zero documentation from 1913, and since pillagers and forgers often concoct such stories to give an inscription an aura of authenticity, this story could actually just be a tall tale told by a forger or some antiquities dealer,” Christopher A. Rollston, chair of the Department of Classical and Near Eastern Languages and Civilizations at George Washington University, told The New York Times in an email.

The tablet had been on display beginning in 2005 at the Living Torah Museum in Brooklyn, New York, but was sold in 2016 for $850,000 with the condition it would be placed on public display.