Imam Ali (peace be upon him): To a heretic who claimed there were contradictions in the Quran, Amir al-Mu'minin (peace be upon him) said: "Concerning the saying of Allah the Exalted: اللهُ یَتَوَفَّی الْأَنْفُسَ حِینَ مَوْتِها [Allah takes the souls at the time of their death] (Zumar/42), and His saying: یَتَوَفَّاکُمْ مَلَکُ الْمَوْتِ [The angel of death appointed over you takes you] (Sajdah/11), and [the verse:] تَوَفَّتْهُ رُسُلُنا [Our messengers take his soul] (An'am/61), and [the verse:] تَتَوَفَّاهُمُ الْمَلائِکَةُ طَیِّبِینَ [Those whom the angels [of death] take while they are pure] (Nahl/32), and [the verse:] الَّذِینَ تَتَوَفَّاهُمُ الْمَلائِکَةُ ظالِمِی أَنْفُسِهِمْ [those whom the angels [of death] take while they have wronged themselves] (Nahl/28) — Allah the Blessed and Exalted is too high and great to undertake that Himself, and the action of His messengers and angels is His own action, because they [continuously] act by His command. And they are those about whom Allah said: اللهُ یَصْطَفِی مِنَ الْمَلائِکَةِ رُسُلًا وَ مِنَ النَّاسِ [Allah chooses messengers from among the angels and from among men] (Hajj/75). So whoever is of the people of obedience, the angels of mercy take charge of taking his soul; and whoever is of the people of disobedience, the angels of punishment take charge of taking his soul. And the angel of death (Azrail) has helpers from the angels of mercy and [angels] of punishment who follow his command, and their action is his action, and everything they do is attributed to him. And when their action is the action of the angel of death (Azrail), the action of the angel of death is the action of Allah, because He takes souls by the hand of whomever He wills, and gives and withholds, and rewards and punishes by the hand of whomever He wills. And the action of His trustees is His action, just as He said: وَ ما تَشاؤُنَ إِلّا أَنْ یَشاءَ اللهُ [And you do not will except that Allah wills]."