Saṃyutta Nikāya 47
Connected Discourses on the Establishments of Mindfulness
41. The Deathless
At Savatthi. “Bhikkhus, dwell with your minds well established in the four establishments of mindfulness. Do not let the Deathless be lost on you.
“In what four? Here, bhikkhus, a bhikkhu dwells contemplating the body in the body … feelings in feelings … mind in mind … phenomena in phenomena, ardent, clearly comprehending, mindful, having removed covetousness and displeasure in regard to the world. Dwell, bhikkhus, with your minds well established in these four establishments of mindfulness. Do not let the Deathless be lost on you.”