Interpretation of Sages

The R”sh at the end of the first p’ of Mikva'ot already says that the L”ms is not necessarily from Moses and not necessarily from Sinai
but apparently ancient traditions that the sages had and wanted to give it validity that would not be undermined and the expression is from the L”ms but not really but an expression for the ancient
as it seems that there are other Rishonim who wrote so and Google

In the past I studied history
All sorts of processes that Homo sapiens went through until it reached superior wisdoms like the Ishta…
For example, appointing a person accused of bribery, fraud, and breach of trust to head a people who are supposed to be morally a light to the nations..
No joke🤔 This is the situation…

Among other things, the invention of parchment… about 2500 years ago
Compared to Judaism, this is the days of Jeremiah the prophet +-
A little before the first destruction.

Oops’ The Hebrews learn from a verse (and the Hebrew Bible?) that one should write on parchment, and how did Moses command us on parchment that would only be invented in about 950 years?
And is it likely that he would command us to send the Torah by email that would be invented in about 3500 years?

I asked the Tahsin and he replied that there was no such thing.
Apparently, it was commanded to write on something that exists (a book), so it was papyrus or some other product.
And since the parchment was invented, this is the thing that exists (a book) and that is what is required.

That is, the LMS or the study of a verse will sometimes be required later on a specific thing and will be discarded before that.