"Whoever memorizes ten of the first verses of Sūrat al-Kahf will be guarded against the Anti-Christ." In another version: “From the concluding verses of Sūrat al-Kahf.” [Muslim]

قَالَ رَسُولُ اللَّهِ ﷺ «مَنْ حَفِظَ عَشْرَ آيَاتٍ مِنْ أَوَّلِ سُورَةِ الكَهْفِ، عُصِمَ مِنَ الدَّجَّالِ». وفي رواية: «مِنْ آخِرِ سُورَةِ الكَهْف». رواه مسلم