Dutiyasūriyūpama sutta: The Simile of the Sun (2nd)

“Mendicants, the dawn is the forerunner and harbinger of the sunrise. In the same way, for a mendicant rational application of mind is the forerunner and harbinger of the arising of the seven awakening factors. A mendicant accomplished in rational application of mind can expect to develop and cultivate the seven awakening factors.

And how does a mendicant with rational application of mind develop and cultivate the seven awakening factors? It’s when a mendicant develops the awakening factors of mindfulness, investigation of principles, energy, rapture, tranquility, immersion, and equanimity, which rely on seclusion, fading away, and cessation, and ripen as letting go. That’s how a mendicant with rational application of mind develops and cultivates the seven awakening factors.”