9.
The Discourse on Feeling
415.
"There are these three feelings, monks.
Which three?
Pleasant feeling, unpleasant feeling, neither-unpleasant-nor-pleasant feeling -
these, monks, are the three feelings.
For the full understanding of these three feelings, monks, the four establishments of mindfulness are to be developed.
"Which four? Here, monks, a monk dwells observing the body in the body, ardent, fully aware, mindful, having removed covetousness and displeasure regarding the world; in feelings... etc. In mind... etc. He dwells observing mental phenomena in mental phenomena, ardent, fully aware, mindful, having removed covetousness and displeasure regarding the world. For the full understanding of these three feelings, monks, these four establishments of mindfulness are to be developed." The ninth.