9.
The Discourse on Meditative Development
405.
"Monks, I will teach the development of the four establishments of mindfulness.
Listen to that."
"What, monks, is the development of the four establishments of mindfulness?
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.
This, monks, is the development of the four establishments of mindfulness."
The ninth.