Mishkat al-Masabih 8 The Excellent Qualities of the Qur’an كتاب فضائل القرآن 37

وَعَن أبي الدَّرْدَاء قَالَ ك قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «مَنْ قَرَأَ ثَلَاثَ آيَاتٍ مِنْ أَوَّلِ الْكَهْفِ عُصِمَ مِنْ فِتْنَةِ الدَّجَّالِ» . رَوَاهُ التِّرْمِذِيُّ وَقَالَ: هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ

Abūd Dardā’ reported God’s messenger as saying, “He who recites three verses at the beginning of al-Kahf will be protected from the trial of the dajjāl .” Tirmidhī transmitted it, saying this is a hasan sahīh tradition.