[369] And what, bhikkhus, is the nutriment (āhāra) for the arising of the unarisen tranquility factor of awakening (passaddhi-sambojjhaṅga), and for the development and fulfillment of the arisen tranquility factor of awakening? There are, bhikkhus, tranquility of body and tranquility of mind (citta): frequently applying careful attention (yoniso manasikāra) to them — this is the nutriment for the arising of the unarisen tranquility factor of awakening, and for the development and fulfillment of the arisen tranquility factor of awakening.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.