Abu Dāwūd mentioned that it was reported with a variation through Qatādah, “…whoever memorizes the concluding verses of Sūrat al-Kahf,” and from Shu’bah via Qatādah, “from the end of Al-Kahf…” Reference:

Sunan ad-Darimi 4323

قَالَ أَبُو دَاوُدَ وَكَذَا قَالَ هِشَامٌ الدَّسْتَوَائِيُّ عَنْ قَتَادَةَ إِلاَّ أَنَّهُ قَالَ ‏"‏ مَنْ حَفِظَ مِنْ خَوَاتِيمِ سُورَةِ الْكَهْفِ ‏"‏ ‏.‏ وَقَالَ شُعْبَةُ عَنْ قَتَادَةَ ‏"‏ مِنْ آخِرِ الْكَهْفِ ‏"‏.