“Bhikkhus, there are these four establishments of mindfulness. What four? Here, bhikkhus, a bhikkhu dwells contemplating the body in the body, ardent, clearly comprehending, mindful, having removed covetousness and displeasure in regard to the world. As he dwells thus contemplating the body in the body, the body is fully understood. Because the body has been fully understood, the Deathless is realized.
“He dwells contemplating feelings in feelings … mind in mind … phenomena in phenomena … having removed covetousness and displeasure in regard to the world. As he dwells thus contemplating phenomena in phenomena, the phenomena are fully understood. Because the phenomena have been fully understood, the Deathless is realized.”