At Sāvatthī.
“Mendicants, there are these four kinds of mindfulness meditation.
What four?
It’s when a mendicant meditates by observing an aspect of the body—keen, aware, and mindful, rid of covetousness and displeasure for the world.
They meditate observing an aspect of feelings …
mind …
principles—keen, aware, and mindful, rid of covetousness and displeasure for the world.
These are the four kinds of mindfulness meditation.”