The Three Gunas
The three qualities of nature that bind the soul.
Sattva (purity), rajas (activity), and tamas (inertia) are the three qualities of prakriti (nature). Their interplay creates the phenomenal world and binds the Self in apparent limitation.
The three gunas born of prakriti bind the imperishable Self to the body.
The gunas explain the varieties of experience in the world.
Shvetashvatara Upanishad