Hasan said: The lack of correspondence between what is hidden and what is manifest, between the tongue and the qalb (the heart), and between what enters the ear and what exits the mouth, are among the signs of nifāq (hypocrisy) ... (Küt, 1, 234; Iḥyāʾ, IV, 212). The subtleties of nifāq, and the shirk (associating partners with God) and weakness of yaqīn (certainty) that arise from a deficiency of tawhid (the oneness of God), produce in the believers a fear of incurring Allah's wrath and of their deeds being rendered void. (Küt, I, 234)
When tawhid is at the door of the house, but shirk is inside the house, this is manifest nifāq. (Fath, 5)
To begin (an action) with the presence of hawā (caprice) without any command is obstinacy and discord; to begin without hawā is agreement and infāq (spending in the way of God); in this situation, to abandon the act is riyāʾ (ostentation) and nifāq. (Futūḥ, 92)