“Bhikkhus, as to internal factors, I do not see any other factor that is so helpful for the arising of the seven factors of enlightenment as this: careful attention. When a bhikkhu is accomplished in careful attention, it is to be expected that he will develop and cultivate the seven factors of enlightenment.” The rest as in §13. sn.v.102
SN46.49: Ajjhattikaṅgasutta
Ajjhattikaṅgasutta: Internal Factor - translated by Bhikkhu Bodhi
Translated by Bhikkhu Bodhi. Source text via SuttaCentral.