Sayyiduna Ibn Umar (may Allah be pleased with them both) narrates that before the Farewell Hajj, we used to discuss it, but we did not know that this would be the farewell meeting from the Prophet (peace and blessings be upon him). On the occasion of the Farewell Hajj, during his sermon, the Prophet (peace and blessings be upon him) made a detailed mention of the "Dajjal" and said: Allah has not sent any prophet into the world except that he warned his nation about the trial of Dajjal. Sayyiduna Nuh (peace be upon him) also warned his nation, and after him, all the noble prophets (peace be upon them) continued to warn. If anything remains hidden from you, this should not remain hidden from you: your Lord is not one-eyed. The Prophet (peace and blessings be upon him) repeated this sentence twice.