When the Prophet (may Allah's peace and blessings be upon him) entered the mosque, he would say: "a‘ūdhu billāhi al-‘azhīm wa biwajhihi al-karīm wa sultānihi al-qadīm min ash-shaytān ar-rajīm" (I seek refuge in Allah, the Majestic, and in His noble Countenance, and in His eternal dominion, from the accursed devil)

Explanation

When the Prophet (may Allah's peace and blessings be upon him) entered the mosque, he would say: "I seek refuge with Allah, the Majestic" i.e., I resort and turn for help to Allah and His attributes. "and in His noble Countenance" i.e., the Generous Giver. "and in His eternal dominion" i.e., His dominance, power, and the ability to vanquish anyone of His creation He wills. 'eternal' i.e., permanent, timeless. "from the accursed devil", who is banished and expelled from the mercy of Allah. i.e., O Allah, protect me from his whisperings, his temptations, his steps, his ideas, his insinuations, and his misguidance, for he is the one who causes misguidance and leads to temptation and ignorance. It was said to ‘Abdullāh ibn ‘Amr: "Is that all?" i.e., did the Prophet (may Allah's peace and blessings be upon him) say that only? He said: Yes. If a person says this supplication upon entering the mosque, the devil will say: He has protected himself from me the whole time, during the day and night.

Benefits

• The Hadīth demonstrates the merit of saying this Dhikr upon entering the mosque and that it protects the one who says it from the devil for the rest of the day.
• It warns of the devil and points out that he lies in wait for the Muslim to misguide and allure him.
• A person is protected from the misguidance and deviation of the devil in proportion to how much he believes in Allah in his heart and how much he is mindful of this supplication and believes Allah's promise that results from it.