Trung Bộ Kinh (Majjhima Nikaya) 3:98
SUJATOTasmātiha, bhikkhave, citte cittānupassī tasmiṁ samaye bhikkhu viharati ātāpī sampajāno satimā vineyya loke abhijjhādomanassaṁ.
That’s why at that time a mendicant is meditating by observing an aspect of the mind—keen, aware, and mindful, rid of covetousness and displeasure for the world.