Riyad as-Salihin

Abud-Darda' (May Allah be pleased with him) reported: The Messenger of Allah (ﷺ) said: "Whoever commits to memory the first ten Ayat of the Surat Al-Kahf, will be protected from (the trial of) Ad-Dajjal (Antichrist)."

[Muslim].

In another narration, the Messenger of Allah (ﷺ) said: "(Whoever commits to memory) the last ten Ayat of Surat Al-Kahf, he will be protected from (the trial of) Ad-Dajjal (Antichrist)."