Four Chapters on One Thing (1-Paṭhamavagga)
AN 1.296–305 Paṭhamavagga
296. “One thing, mendicants, when developed and cultivated, leads solely to disillusionment, dispassion, cessation, peace, insight, awakening, and extinguishment. What one thing? Recollection of the Buddha. This one thing, when developed and cultivated, leads solely to disillusionment, dispassion, cessation, peace, insight, awakening, and extinguishment.”