Digha Nikaya 2:90
SUJATOKathañca pana, bhikkhave, bhikkhu citte cittānupassī viharati?
And how does a mendicant meditate observing an aspect of the mind?
Kathañca pana, bhikkhave, bhikkhu citte cittānupassī viharati?
And how does a mendicant meditate observing an aspect of the mind?