Musannaf Ibn Abi Shayba 37:287

Abu Mu’awiyah narrated to us, from al-A’mash, from ‘Amr ibn Murrah, from Abu al-Bakhtari, from Hudhayfah, who said: The hearts are four: A heart that is overturned (musaffah), and that is the heart of the hypocrite. A heart that is wrapped (aghlaf), and that is the heart of the disbeliever. A heart that is bare (ajrad), as if there is a lamp in it shining, and that is the heart of the believer. And a heart in which there is hypocrisy and faith; its likeness is like a sore that is supplied by pus and blood, and its likeness is like a tree that is watered by foul water and good water, so whichever water overcomes it, it prevails.