Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates: We used to talk about the Farewell Hajj, and we did not know that it was the Prophet's (peace and blessings be upon him) farewell Hajj. When the occasion of the Farewell Hajj came, he delivered a sermon, mentioned the Dajjal and spoke at length about him. Then he (peace and blessings be upon him) said: "Every prophet whom Allah Almighty sent warned his nation about the Dajjal. Sayyiduna Nuh (peace be upon him) did so, and the prophets who came after him did so too. Beware! However much of his affair remains hidden from you, this should not remain hidden from you: that your Lord is not one-eyed." (Al-Haythami says:) I say: part of it is mentioned in the "Sahih".
Ahmad recorded it, and its narrators are the narrators of the Sahih.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الفتن - أعاذنا الله منها / 12511