Digha Nikaya (Coleção dos Discursos Longos) 2:10
SUJATOvedanāsu vedanānupassī viharati ātāpī sampajāno satimā vineyya loke abhijjhādomanassaṁ,
They meditate observing an aspect of feelings—keen, aware, and mindful, rid of covetousness and displeasure for the world.