“I heard al-Mufadhdhal bin Umar asking Abu Abdullah as-Sadiq (as): “Does Allah impose (upon people) to obey someone and then the divine revelation keeps that secret?” Abu Abdullah as-Sadiq (as) said: “Allah is more glorified, merciful and kinder to His people than to impose upon them obeying someone but the divine revelation keeps that secret day and night.” Then his son Abul Hasan Musa (as) appeared. Abu Abdullah as-Sadiq (as) said to al-Mufadhdhal: “Would you like to look at the keeper of Imam Ali’s book?” Al-Mufadhdhal said: “And is there anything else that makes me more delighted than this?!” Abu Abdullah as-Sadiq (as) said: “This is the keeper of Ali’s hidden book, about which Allah has said, ‘None shall touch it save the purified ones.’”