Trung Bộ Kinh (Majjhima Nikaya) 3:96
SUJATOcitte cittānupassī, bhikkhave, tasmiṁ samaye bhikkhu viharati ātāpī sampajāno satimā vineyya loke abhijjhādomanassaṁ.
at that time they meditate observing an aspect of the mind—keen, aware, and mindful, rid of covetousness and displeasure for the world.