Dhamma-cakkapavattana-sutta, “The Setting in Motion of the Wheel of Dhamma,” is the title of what is regarded as the Buddha’s First Sermon (see Buddhism), preached in the Dear Park at Isipatana (Sarnath), near Benares. It contains his essential teaching on the avoidance of the extremes of indulgence and asceticism, the Four Noble Truths, and the Eightfold Path (astangika-marga). It is one of the great four events in the Buddha’s life. The other three are his birth, his enlightenment, and his passing into parinibbana, final nibbana at death. The sermon is contained in Sanyutta-Nikaya 5, 420. A.G.H.
Bowker, John, The Oxford Dictionary of World Religions, New York, Oxford University Press, 1997, p. 274