10.
The Discourse on the External Factor
231.
"Taking an external factor into account, monks, I do not perceive any other single factor for the arising of the seven factors of enlightenment, as does -
monks, good friendship.
For a monk with good friends, monks, this is to be expected -
he will develop the seven factors of enlightenment, he will cultivate the seven factors of enlightenment.
And how, monks, does a monk with good friends develop the seven factors of enlightenment, cultivate the seven factors of enlightenment?
Here, monks, a monk develops the enlightenment factor of mindfulness, based upon seclusion, etc.
He develops the enlightenment factor of equanimity, based upon seclusion, based upon dispassion, based upon cessation, maturing in release.
Thus, monks, a monk with good friends develops the seven factors of enlightenment, cultivates the seven factors of enlightenment."
The tenth.