The Prophet ﷺ said, "Whoever memorizes the first ten verses of Surah al-Kahf will be protected from the Dajjal."
أن النبي ﷺ قال: من حفظ عشر آيات من أول سورة الكهف عصم من الدجال.
Muslim narrated it in the Book of the Traveler's Prayer (809) from Muhammad bin Muthanna, who said, Muaz bin Hisham narrated to us, my father narrated to me from Qatada, from Salim bin Abu Jaad Ghatafani, from Madan bin Abu Talha Yamuri, from Abu Darda, and he related it.Muslim also narrated it from Muhammad bin Muthanna and Ibn Bashar, who both said, Muhammad bin Jafar narrated to us, Shuba narrated to us. Another chain, Zuhayr bin Harb narrated to me, Abdul-Rahman bin Mahdi narrated to us, Hammam narrated to us, both from Qatada with this same chain of transmission. Shuba said, "from the end of Kahf," while Hammam said, "from the beginning of Kahf," as Hisham had said. This concludes the account.So Hammam, who is Ibn Yahya bin Dinar Awdhi, and Hisham, who is Ibn Abu Abdullah Sanbar Dastawai, agree on mentioning "the beginning of Kahf," and both are reliable and firmly established narrators among the men of the two sheikhs. This is the correct version. They are corroborated in this by Saeed bin Abu Aruba, as recorded by Ahmad (27540), and by Shayban bin Abdul-Rahman Nahwi, also recorded by him (27541), both narrating from Qatada and saying, "the ten from the beginning of Kahf." This is also supported by the hadith of Nawas bin Saman that follows.Shuba, however, was inconsistent, saying, as reported by Muslim through the route of Muhammad bin Jafar from him, "from the end of Kahf." Tirmidhi (3104) also narrated it through the very same route, from Muhammad bin Jafar from Shuba, and in it he said, "three verses from the beginning of Kahf." Nasai also narrated it in Kubra (8025) through the very same route of Muhammad bin Jafar, and in it he said, "whoever recites ten verses from Surah Kahf," without specifying whether from the end of Kahf or the beginning of Kahf.Muhammad bin Jafar is Ghundar, one of the most reliable transmitters of Shuba's narrations. So it appears that the error originated from Shuba himself, and not from anyone else.Nasai also narrated it in Amal al-Yawm wal-Layla (948) from Muhammad bin Abdul-Ala, who said, Khalid narrated to us, who said, Shuba narrated to us, who said, Qatada informed me, from Salim bin Abu Jaad, from Madan, from Thawban, as a marfu report, "Whoever recites the last ten verses of Surah Kahf, it will be a protection for him against Dajjal." Khalid here is Ibn Harith Hujaymi, and although he is reliable, he ranks below Muhammad bin Jafar Ghundar. So perhaps this error originated from him, in that he attributed the hadith of Abu Darda to Thawban.