The Satipaṭṭhāna SuttaM.i.56ff. (Majjhima Nikaya 10: The Discourse on the Establishing of Mindfulness), and the subsequently created Mahāsatipaṭṭhāna SuttaD.ii.290ff (Dīgha Nikāya 22: The Great Discourse on the Establishing of Mindfulness), are two of the most celebrated and widely studied discourses in the Pāli Canon of Theravada Buddhism, acting as the foundation for contemporary vipassana meditational practice. The Pāli texts of the Satipaṭṭhāna Sutta and the Mahāsatipaṭṭhāna Sutta are largely similar in content; the main difference being a section about the Four Noble Truths (Catu Ariya Sacca) in the Observation of Phenomena (Dhammānupassana), which is greatly expanded in the Mahāsatipaṭṭhāna Sutta. These suttas (discourses) stress the practice of sati (mindfulness) "for the purification of beings, for the overcoming of sorrow and lamentation, for the extinguishing of suffering and grief, for walking on the path of truth, for the realization of nibbāna."
