…hateful—the very thoughts of unbelief that Satan casts into the heart of a believer. They said, “O Messenger of Allah, one of us finds within himself notions that he would rather be burned to ashes or hurled from the sky to earth than utter aloud.” He replied, “That is pure faith.” In another wording he said, “Praise be to Allah, who reduced Satan’s scheme to mere whispering.”

The two Sahihs also narrate that the Prophet—may Allah bless him and grant him peace—said: “When the mu’adhdhin gives the call to prayer, Satan turns and flees, releasing wind so that he will not hear the adhan. When the call is finished he returns; when the iqamah is pronounced he turns away again, and once it is over he comes back until he insinuates himself between a man and his heart, saying, ‘Remember such-and-such, remember such-and-such,’ things he had never thought of before, until the worshiper no longer knows how many units he has prayed. If any of you experiences that, let him perform two prostrations.” Thus the Prophet informed us that Satan whispers during the prayer, yet he did not require the prayer to be repeated.

Corrupt beliefs and evil intentions arise through the devils of humankind and jinn, whereas sound beliefs and praiseworthy intentions may come through the angels and the righteous among people. Speech affects the listener’s heart: the speaker is the active agent. If the listener is receptive, the words are imprinted on his heart; if he is not, they leave no trace.

Refutation of the claim that the unseen can be known without the mediation of the Prophets:

What is asserted by certain esoteric groups—the Bāṭinite branch of the Shiʿah such as the authors of the Epistles of the Brethren of Purity, the esoteric Sufis like Ibn Sabʿīn, Ibn ʿArabī, and others—and what appears in the writings of Abū Ḥāmid al-Ghazālī and others who engage in spiritual exercises, purification of the heart, and refinement of the soul through virtuous character, namely that they can come to know…