Israel, the covenant people of God, Who Were There First, understand something or other about Scripture... cf this excerpt on the advantages of the Oral Torah, formed and transmitted as Jewish Tradition, as opposed to merely dealing with the written text:
"If the entire Torah would have been given in writing, everyone would be able to interpret it as he desired. This would lead to division and discord among people who followed the Torah in different ways. The Oral Torah, on the other hand, would require a central authority to preserve it, thus assuring the unity of Israel..."
More on point here, from Shavuot.