Kitab al-Kafi
Rest assured, no one has a special relationship with God. Whoever denies me is not from my (community). The appearance of the Relief depends solely upon God. Therefore, those who propose a certain time for it are liars. As to the benefit of my existence in occultation, it is like the benefit of the sun behind the clouds where the eyes do not see it. - "Kitab al-Kafi", Muhammad ibn Ya'qub al-Kulayni