Sayyiduna Mihjan bin al-Adra' (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him), while addressing the people, said: "The Day of Purification! What is the Day of Purification? The Day of Purification! What is the Day of Purification? The Day of Purification! What is the Day of Purification?" He said this three times. It was asked: "What is the Day of Purification?" The Prophet (peace and blessings be upon him) said: "The Dajjal will come. He will climb Mount Uhud and say to his companions: 'Do you see this white palace? This is the mosque of Ahmad.' Then he will come to Madinah and find at every road into Madinah an angel with a drawn sword. Then he will come to the salt marsh of al-Juruf and pitch his canopy. Then Madinah will be shaken by three earthquakes, and no hypocrite man or hypocrite woman, nor any sinful man or sinful woman, will remain without going out and going over to him. That will be the Day of Deliverance (or of Purification)."
Imam Ahmad recorded it, and its narrators are the narrators of the Sahih.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الحج / 5831
Hadith Gradingمحدثین:إسنادہ صحیح۔
Hadith Takhrij«اخرجه احمد فى المسند (338/4) ، أخرجه مسند أحمد برقم: 18496، وأخرجه المستدرك على الصحيحين برقم: 8675»