[815] Bhikkhus, I will teach you the establishment of mindfulness (satipaṭṭhāna), the development (bhāvanā) of the establishment of mindfulness, and the way of practice (paṭipadā) leading to the development of the establishment of mindfulness. Listen to that.
And what, bhikkhus, is the establishment of mindfulness? Here, bhikkhus, a bhikkhu dwells contemplating the body in the body (kāyānupassanā), ardent (ātāpī), clearly comprehending (sampajāno), mindful (satimā), having removed covetousness and grief regarding the world (abhijjhā-domanassa). In feelings (vedanā) … in the mind (citta) … he dwells contemplating dhammas in dhammas, ardent, clearly comprehending, mindful, having removed covetousness and grief regarding the world. This, bhikkhus, is called the establishment of mindfulness.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.