Hadithcore
Sahih Muslim, 809 a
sahih

Abu Darda' reported Allah's Messenger (ﷺ) as saying:

If anyone learns by heart the first ten verses of the Surah al-Kahf, he will be protected from the Dajjal.

وَحَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا مُعَاذُ بْنُ هِشَامٍ، حَدَّثَنِي أَبِي، عَنْ قَتَادَةَ، عَنْ سَالِمِ، بْنِ أَبِي الْجَعْدِ الْغَطَفَانِيِّ عَنْ مَعْدَانَ بْنِ أَبِي طَلْحَةَ الْيَعْمَرِيِّ، عَنْ أَبِي الدَّرْدَاءِ، أَنَّ النَّبِيَّ صلى الله عليه وسلم قَالَ ‏

‏ مَنْ حَفِظَ عَشْرَ آيَاتٍ مِنْ أَوَّلِ سُورَةِ الْكَهْفِ عُصِمَ مِنَ الدَّجَّالِ ‏

References2 variants
In-Book Reference
Book 6, Hadith 311
USC-MSA web (English) reference
Book 4, Hadith 1766 (deprecated numbering scheme)
Sharh · explanationclick to expand
Recitation of the Qur’an brings goodness and blessing for those who recite it, as it is the extended rope of Allah, causing tranquility of the soul and an abundance of rewards, and it protects a servant from the distresses and trials of worldly life and the horrors and hardships on the Day of Judgment. In this Hadīth, the Prophet (may Allah's peace and blessings be upon him) says that whoever memorizes ten verses from the beginning of Surat al-Kahf, Allah will guard, protect, and preserve him from the trial of the Dajjāl, who will emerge at the end of time and claim to be God. The Dajjāl originally refers to someone who often engages in lying and deception. His emergence is one of the major signs of the Day of Judgment, and his trial is the gravest on earth from the creation of Adam to the coming of the Hour, as Allah Almighty will enable him to perform some miracles whereby he will mislead his followers. Verily, the memorization of these verses is a cause of protection against the Dajjāl. It was said: This is due to the wonders and miracles existing in these verses. So, whoever knows them will not wonder at the matter of the Dajjāl or be misled by him; and he will patiently endure the trials of the Dajjāl and his apparent bliss and punishment; or that the protection from the Dajjāl is granted by Allah to those who memorize these verses. Also, there are means of protection against the trial of the Dajjāl, which are not mentioned in this Hadīth, but are authentically reported from the Messenger of Allah (may Allah's peace and blessings be upon him) in other Hadīths: Knowing the names and attributes of Allah, which makes one know that the Dajjāl is a human being who eats and drinks, and Allah is far Exalted above that; the Dajjāl is one-eyed, whereas Allah is not one-eyed; and no one sees his Lord until he dies, whereas the people, including the believers and disbelievers, will see the Dajjāl when he emerges. It also includes the pursuit of Allah's refuge from the trial of the Dajjāl, particularly in prayer, as reported in a Hadīth by ‘Ā’ishah (may Allah be pleased with her) in the Two Sahīh Collections that the Prophet (may Allah's peace and blessings be upon him) used to supplicate in prayer: "O Allah, I seek refuge with You from the punishment of the grave, and I seek refuge with You from the trial of the Dajjāl." And it also includes fleeing and turning away from the Dajjāl, for those who will be present at his time, given the suspicions and amazing supernatural incidents that appear with him and by which a person might be tempted. In the Hadīth: The merit of the ten verses at the beginning of Surat al-Kahf. And in it: Clarifying that the trial of the Dajjāl is so severe that protection against him is needed.