If the earliest known copy of a given Biblical passage dates from, say, 100 BC; how certain can we be that that is not the original of that passage? In other words, can we be sure it is a copy of an older manuscript. (Ignore issues of grammar, language, poetic style that would necessarily be older.) For example, if the earliest known manuscript of Ezra 1:3 dated to 100 BC and it's language and composition was consistent with those used at that time, could we be sure that that passage was olde