Sayyiduna Abu Bakrah (may Allah be pleased with him) says: Earlier, people used to talk a great deal about Musaylimah; this was before the Prophet (peace and blessings be upon him) had said anything about him. Once the Prophet (peace and blessings be upon him) stood up among the people to deliver a sermon, and he (peace and blessings be upon him) said: "Amma ba'd (to proceed): The matter of this man whom you mention so often is that he is one of the thirty liars who will emerge before the Hour. And the terror of the Dajjal will reach every city except Madinah, for at each of its routes there will be two angels who will ward off the terror of the Dajjal from this city."
Imam Ahmad and Imam al-Tabarani recorded it; the narrators of one of the various chains of Imam Ahmad and Imam al-Tabarani are the narrators of the Sahih.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الفتن - أعاذنا الله منها / 12482