The remainder are biblical commentaries, prayers, prophecies, hymns, and sectarian rules of conduct and worship. One scroll that contains a major portion of the book of Isaiah, for example, shows only 13 minor variations from the modern version. The sacred texts, he theorizes, were updated occasionally with new theological ideas or to explain changing historical circumstances. Only later, when doctrinal debates arose between Christians and Jews, did religious leaders settle on preferred editions of the Hebrew Bible. Roughly half the Old Testament texts at Qumran contain passages that do not appear in modern translations, or they omit passages that appear in later texts.
Some variations are startling.
The texts claim King David as their author. Most scholars doubt that David actually wrote the unfamiliar Psalms. Even so, says Ulrich, it is likely the collection was accepted as a biblical book by its readers 2,000 years ago. Matthew cites five ancient prophecies that he says were fulfilled by the birth of Jesus. Four of those appear in the traditional Hebrew Bible.