`Sayyiduna Jabir bin Abdullah (may Allah be pleased with him) swore that Ibn Sayyad is the Dajjal. I (the narrator Muhammad bin Munkadir) said, "Do you swear an oath?" He said, "Yes! I heard Sayyiduna Umar (may Allah be pleased with him) swear an oath about this in the presence of the Prophet (peace and blessings of Allah be upon him), and the Prophet (peace and blessings of Allah be upon him) did not forbid him."