From the Upanishads
आत्मानं रथिनं विद्धि शरीरं रथमेव तु
ātmānaṁ rathinaṁ viddhi śarīraṁ ratham eva tu

“Know the self as the rider, and the body as the chariot.”

Katha Upanishad 1.3.3
In plain terms

One of the oldest pictures of a person ever drawn: the body a chariot, the senses its horses, the mind the reins, and you the rider it all belongs to.

The picture is a diagnostic. On any given afternoon you can ask who is driving, the rider or the horses, and know at once which kind of day you are having. This site's Reflect page is built on this very verse.

All the verses, by the moment you need them