At Sāvatthī.
There the Buddha said:
“Rightly speaking, mendicants, you’d call the five hindrances a ‘heap of the unskillful’. For these five hindrances are entirely a heap of the unskillful. What five? The hindrances of sensual desire, ill will, dullness and drowsiness, restlessness and remorse, and doubt. Rightly speaking, you’d call these five hindrances a ‘heap of the unskillful’. For these five hindrances are entirely a heap of the unskillful.
Rightly speaking, you’d call these four kinds of mindfulness meditation a ‘heap of the skillful’. For these four kinds of mindfulness meditation are entirely a heap of the skillful. 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 … They meditate observing an aspect of the mind … They meditate observing an aspect of principles—keen, aware, and mindful, rid of covetousness and displeasure for the world. Rightly speaking, you’d call these four kinds of mindfulness meditation a ‘heap of the skillful’. For these four kinds of mindfulness meditation are entirely a heap of the skillful.”