Riyad as-Salihin 1021
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)."
وعن أبي الدرداء رضي الله عنه أن رسول الله صلى الله عليه وسلم قال‏:‏ ‏"‏من حفظ عشر آيات من أول سورة الكهف، عصم من الدجال‏"‏ وفي رواية‏:‏ ‏"‏من آخر سورة الكهف‏"‏ ‏(‏‏(‏رواهما مسلم‏)‏‏)‏‏.‏