Then a certain bhikkhu approached the Blessed One…. Sitting to one side, that bhikkhu said to the Blessed One: “Venerable sir, it is said, ‘factors of enlightenment, factors of enlightenment.’ In what sense are they called factors of enlightenment?”
“They lead to enlightenment, bhikkhu, therefore they are called factors of enlightenment. Here, bhikkhu, one develops the enlightenment factor of mindfulness, which is based upon seclusion, dispassion, and cessation, maturing in release…. One develops the enlightenment factor of equanimity, which is based upon seclusion, dispassion, and cessation, maturing in release. They lead to enlightenment, bhikkhu, therefore they are called factors of enlightenment.”