From him, from Hammad from Hariz from Al-Fudayl, who said: I asked Abu Ja‘far عليه السلام about the saying of Allah سبحانه وتعالى, the Exalted: “Those who guard their prayers” (Surah Al-Ma‘arij 70:34) & (Surah Al-Mu'minun 23:9). Imam عليه السلام said: “That refers to the obligatory prayers.” I asked: (about) “Those who are constant in their prayers” (Surah Al-Ma‘arij 70:23). Imam عليه السلام said: “That refers to the supererogatory (nafilah) prayer.”