Reb Mendel of Kotzk said:[1]
There is a saying that a book without a preface is like a body without a soul. All books have a preface, but what is the preface to Torah?
However, G-d too made a preface for the Torah—“the way of the world,” derech eretz which preceded the giving of the Torah. (Vayikra Rabba 9:3)
[1] Emet Mkotzk Titzmach Pg. 83