A set of 66 stone tiles known as the 'Ezekiel Plates,' believed to have come from the prophet Ezekiel's traditional tomb along the Euphrates River in Iraq, are in the process of being dated by modern technological methods to finally establish whether they should be considered on a par with the Isaiah Scroll as among the oldest existing biblical texts ever found.
Until now, estimates of their age have varied widely. According to the British Museum, the plates could be anywhere between 300 to 2000 years old. In any event, taken together the series of 66 stone plates contain the entire Book of Ezekiel, with only a few notable variances in wording compared to today's accepted Hebrew text. These do not change the message of the prophet to any extent, but they may provide hidden clues to Jewish scholars on certain mysteries surrounding the prophet.
http://www.jpost.com/ChristianInIsrael/Features/Article.aspx?id=218495
Editorial note: This mentions the Dead Sea Scrolls as the oldest known Hebrew text. There is actually one much older: The Silver Scrolls discovered by ABR staff member Gordon Franz at Ketef Hinnom.