Post History

Why does the Written Torah include construction details?

The understanding I have is that every word in the Torah (5 books) is important and what is related there is essential to building a Jewish world-view. Therefore, the stories and laws are to be pored over to glean every lesson available. Though the text spells out certain things, much is also left to an oral tradition which is full of equally necessary things. For some reason, they were left out of the written text.

Initially my question was general -- why were certain things in one (written) text and other things were transmitted orally, but yesterday's laining gave me specific pause.

We don't have an understanding of shechita, the melachot on shabbat or what totafot are from the written text alone because those details were saved for the oral law. And yet the Torah takes a number of verses to give the dimensions and details for building the mishkan in the desert! Why is it important to know the width of a plank of wood (especially if, in the future, when the 3rd temple is built, we won't be building a mishkan again)? Why would such (mundane) details as rings and staves be included at length while more practical ideas which define our daily life are not?

I know that he Torah isn't a story book or a history book, but it also isn't a construction manual. I also know that the material in the oral law is as valid, contemporaneous and authoritative as the written stuff, but I still can't figure out why I need the building details at all, let alone in the written text.