The most esteemed commentary in all of Pali literature,  The Path of Purification, or Visuddhimagga, is a systematic examination and condensation of Budhist doctrine and meditation technique. The various teachings of the Buddha found throughout the Pali Canon are organized in a clear, comprehensive path leading to the final goal, nibbana, the state of complete purification. In the course of his treatise, Buddhaghosa gives full and detailed instructions on the forty subjects of meditation aimed at concentration, an elaborate account of the Buddhist Abhidhamma philosophy, and explicit descriptions of the stages of insight culminating in final liberation.
The author, Bhadantacariya Buddhaghosa, composed the Visuddhimagga in the early part of the fifth century A.D. The India-born monk-scholar travelled to Sri Lanka to translate into Pali the extensive Sinhalese commentaries preserved there. His crystallization of the entire Pali Canon reinvigorated Theraveda Buddhism in India and Sri Lanka. The Visuddhimagga still shines clearly today in this brilliant 1956 translation by the British-born monk, Bhikkhu Nanamoli, which in itself is considered an outstanding achievement of Pali scholarship of the 20th century.