Imam Ali's Nightly Vigil at the Masjid Kufa

Of the three assassins, it was Abdur Rahman who had the easiest task. Ali had long been accustomed to spend night after night alone in the mosque, in prayer and meditation. It was not unusual for him to kneel on his prayer mat at sunset and there pass the whole night long in prayer until the dawn of the next day. This habit of his had occasioned alarm among his followers who were sincerely devoted to him. “Is it not sheer folly,” they said, “to attend the mosque at night, unaccompanied and without escort, in the midst of so many enemies? We who are loyal to him will take precautions for his safety which he himself neglects.” A small group took it in turns to guard Ali, unknown to the Caliph himself.
When eventually he was apprised of the existence of this volunteer guard he said to them, “Are you here to defend me from the decrees of heaven or against the hostilities of my enemies? “Lord”, they replied, “who can defend you against the decrees of heaven! We guard you against the evil plans of your enemies and their treacherous designs.
We are only here to see that no one injures or assails you.” Then said Ali; “you must remember that the fate of even the most insignificant creature on this earth is controlled and supervised by God.” With this, he dismissed the guard and forbade their nightly vigils