[754] On one occasion the Blessed One was dwelling at Uruvelā, on the bank of the river Nerañjarā, at the foot of the Ajapāla Banyan tree, just after his first full awakening. Then, while the Blessed One was alone in seclusion, a reflection arose in his mind thus: "This is the one-way path (ekāyana magga) for the purification of beings, for the surmounting of sorrow and lamentation, for the passing away of suffering (dukkha) and grief, for the attainment of the true way (ñāya), for the realization of Nibbāna — that is, the four establishments of mindfulness (satipaṭṭhāna). What four? A bhikkhu should dwell contemplating the body in the body, ardent, clearly comprehending, mindful, having removed covetousness and grief regarding the world. Or a bhikkhu … regarding feelings (vedanā) … Or a bhikkhu … regarding the mind (citta) … Or a bhikkhu should dwell contemplating dhammas in dhammas, ardent, clearly comprehending, mindful, having removed covetousness and grief regarding the world. This is the one-way path for the purification of beings, for the surmounting of sorrow and lamentation, for the passing away of suffering and grief, for the attainment of the true way, for the realization of Nibbāna — that is, the four establishments of mindfulness."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.