The earliest known tablet bearing the 10 Commandments realised $850,000 at Heritage Auctions last night.
The remarkable lot dates to around AD 300-500 and originates from western Israel, where it was probably displayed outside a synagogue.
It was discovered during excavations for a railroad in 1913, near to the ancient city of Yavne.
There are only five early examples of the biblical proclamation - known as the Samaritan Decalogues - that date to before the Muslim invasion in the 7th century AD.
This is the only one still in private hands.
Two phone buyers battled for the stone, almost tripling its $250,000 opening bid.
The tablet is of such historical importance that it was sold with a caveat.
David Michaels of Heritage explains: "Although officially deemed a 'National Treasure' of Israel, the Israeli Antiquities Authority (IAA) approved export of the piece to the United States in 2005 on the condition that it be displayed in a public museum, a condition that still remains in effect.
"The sale of this tablet does not mean it will be hidden away from the public.
"The new owner is under obligation to display the tablet for the benefit of the public."
Elsewhere in the sale a rare early Hanukkah menorah (circa AD 70-200) achieved $17,500.
That places it only a couple of centuries after the origin of the Hanukkah feast, which celebrates the re-consecration of the Holy Temple after the Jews forced the Greeks from Jerusalem in 165 BC.
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