But your point was that the Jews were depending on oral tradition. That verse shows that to not be the case. They were literate and wrote things down.
God obviously saw the need and importance of writing things down. HE wrote the Ten Commandments on tablets of stone for goodness sake. Twice.
How much more permanent can you get?
Did the history of the Jews begin with Moses?
Scripture does more than just give us the Law.
It tells the Jewish people how they got there and why they are to keep the Law. Without it, without that belief that God is the Almighty Creator who chose them as His people, why would they follow the Law?
It is the same for us with Jesus. We learn from the OT, how we got here, why we believe and then once we believe we follow His commands so that we will remain in Him and He in us.
It is not the writing down of things that we are discussing.
It is whether or not each individual believer must READ Scripture to believe and be saved.
My point, to clarify, was that the Jewish people did not write all of their history as it happened and it was oral Tradition that even Moses depended on to know that Israel is the Chosen People of God. There was nothing written before Moses!
So, what Moses knew he knew from oral teaching. Do you see now why it would be of the utmost importance that what was passed orally was preserved as accurately as possible?
Then when God did first write the Ten Commandments and instructed Moses to write the first five books of the OT, we trust that what was written was inerrant by the working of God through Moses.
When he wrote those things which came before him, do you imagine he was knowing them for the first time? Or was he writing the history he had heard orally passed down to him by his ancestors.