It was reported that the Messenger of Allah ﷺ said, “Whoever reads Sūrat al-Kahf on the day of Jumu’ah, a light will shine for him between the two Fridays.” Reference:

Mustadrak al-Hakim; Sahih at-Targhib wa at-Tarhib 736

وَعَنْ أَبِي سَعِيدٍ رَضِيَ اللَّهُ عَنْهُ أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: من قَرَأَ سُورَة الْكَهْف فِي يَوْم الْجُمُعَة أَضَاء لَهُ النُّور مَا بَيْنَ الْجُمعَتَيْنِ.