The Messenger of Allah ﷺ mentioned Dajjal and said, "If he comes out while I am still among you, I will be the one to contend with him on your behalf. But if he comes out when I am no longer among you, then each man must contend with him for himself, and Allah will be my successor over every Muslim. Whoever among you meets him should recite over him the opening verses of Surah Kahf, for they are your protection from his trial."We asked, "How long will he remain on the earth?"He said, "Forty days. One day like a year, one day like a month, one day like a week, and the rest of his days like your ordinary days."We said, "Messenger of Allah, on that day which is like a year, will one day and night's prayers be enough for us?"He said, "No, calculate for it the proper measure. Then Isa the son of Maryam will descend at the white minaret east of Damascus, and he will overtake him at the gate of Ludd and kill him."
حدثنا عيسى بن محمد حدثنا ضمرة عن السيباني عن عمرو بن عبد الله عن أبي أمامة عن النبي ﷺ نحوه وذكر الصلوات مثل معناه
[Its isnad is hasan] Ibn Majah narrated it in "Fitan," chapter on the fitnah of Dajjal and the emergence of Isa bin Maryam and the emergence of Yajuj and Majuj, hadith no. 4077, from the hadith of Abu Zura Sibani, in a lengthier form.