Saṁyutta Nikāya 52.18 2. Dutiyavagga Nānādhātusutta

“Imesañca panāhaṁ, āvuso, catunnaṁ satipaṭṭhānānaṁ bhāvitattā bahulīkatattā anekadhātunānādhātulokaṁ yathābhūtaṁ pajānāmī”ti.

“… And it’s because of developing and cultivating these four kinds of mindfulness meditation that I truly understand the world with its many and diverse elements.”

Aṭṭhamaṁ.