The Old and New Testaments have come to us by rather different historical routes.
One difference concerns the gap in time between the writing of the original texts (the autographs) and the earliest ancient copies we actually possess. For the New Testament, the gap is around a century, since our first manuscript fragments are dated to the second century AD (the New Testament itself was completed by the end of the first century AD). By contrast, the gap for the Old Testament is far greater.
While we do have fragments of Greek translations of the Old Testament dated to the first and second centuries BC, until the Dead Sea Scrolls were discovered in 1946–47, our earliest Hebrew manuscripts (with the exception of the brief Nash papyrus) were dated to roughly a thousand years after Christ. (Consider that the Old Testament itself had already been completed several centuries before Christ.) Even with the fragmentary Dead Sea Scrolls, we are talking about a gap of at least several centuries since the latest books of the Old Testament had been written. This is to say nothing of the earliest portions of the Old Testament which were written many centuries earlier.
For this reason, scholars were understandably excited to discover the now famous Ketef Hinnom silver amulets in 1979. These tiny texts were found in an archaeological excavation on the slopes of a rocky hill in the vicinity of the Hinnom Valley, which wraps around the southwestern corner of the Old City of Jerusalem. The Hinnom Valley, also known by its Aramaic name, Gehenna, was the place where several Judaean kings had sacrificed their children by fire (Jeremiah 7:31). It was here in a rock-cut tomb that two tiny silver scrolls, resembling cigarette butts, were discovered rolled up and in fragile condition. When carefully unrolled by scholars, they discovered that both were inscribed with the faint letters of an ancient Hebrew script. This old script was used by Israelites prior to the Babylonian captivity, when it was replaced by the recognisable square script of the Dead Sea Scrolls, which is still in use today.
Based on a palaeographic analysis of the style of handwriting in the letters, scholars have suggested that these amulets date back to around the second half of the seventh century BC. This would place them around the time of biblical figures like king Josiah and the prophet Jeremiah. Amazingly, the very brief and fragmentary contents of the silver amulets contained excerpts from Aaron’s blessing in Numbers 6:24-26, as well as phrases from Deuteronomy 7:9 (also paralleled in Nehemiah 1:5 and Daniel 9:4). As such, these tiny texts are by far the earliest quotations of the Bible we possess, and the only ones that date prior to the Babylonian exile.