Bhagavad Gita, Chapter 15, Verse 1

The Deity said: They speak of an eternal Ashvattha rooted above and branching below, whose leaves are the Vedas; he who knows it, is a Veda-knower.

A real, upside-down image opens this chapter, roots reaching up instead of down.

Describing the world as a tree with its roots above turns something familiar completely on its head. Real understanding here starts by seeing this world from an unfamiliar angle.