This is what I have heard. “Monks, I consider no other single quality to be so much the cause of the arising of wholesome qualities that have not arisen and the wasting away of unwholesome qualities that have arisen as this: attentiveness. When a monk is attentive, wholesome qualities that have not arisen arise and unwholesome qualities that have arisen waste away.”

From Sayings of the Buddha: A Selection of Suttas from the Pali Nikayas, translated by Rupert Gethin, Oxford: Oxford University Press, 2008, p. 250.