The Related Suttas Collection 46.13

2. Sick

The Simile of the Sun (2nd)

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

And how does a bhikkhu with rational application of mind develop and cultivate the seven awakening factors? It’s when a bhikkhu 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 bhikkhu with rational application of mind develops and cultivates the seven awakening factors.”