Volume 9, Book 92, Number 453:
Narrated Muhammad bin Al-Munkadir:
I saw Jabir bin ‘Abdullah swearing by Allah that Ibn Sayyad was the Dajjal. I said to Jabir, “How
can you swear by Allah?” Jabir said, “I have heard ‘Umar swearing by Allah regarding this matter in
the presence of the Prophet and the Prophet did not disapprove of it.”