Talk of ancient handwriting set the science world aflutter on Tuesday thanks to a new study that used mathematical analysis of clay-pot letters to determine that there was a “high level of literacy” in ancient Israel. The story, first reported in The New York Times, generated breathless headlines: “Bible was written way earlier than we thought,” announced sciencealert. “Bible is really old,” championed livescience.

Not so fast.

The study, published this week in the Proceedings of the National Academy of Sciences, used a cache of 100 letters written in ink on clay pottery and unearthed during the excavation of a fort in Arad, near the Dead Sea. The clay letters, known as ostraca, were dated to 600 BCE, before the destruction of Jerusalem by the Babylonian king Nebuchadnezzar II in 586 BCE. Many (though by no means all) scholars believe that it was during the Israeli exile following Nebuchadnezzar’s conquest that many parts of the Bible came to be written down.