It is narrated from Sayyiduna Umar (may Allah be pleased with him) that I heard the Messenger of Allah (peace and blessings be upon him) say: "A time will surely come when a rider will circle around the surroundings and outskirts of Madinah Munawwarah and will say, 'There used to be many believers living here.'"
Hadith Referenceمسند احمد / مسند الخلفاء الراشدين / 124
Hadith Gradingحکم دارالسلام:حسن لغيره ، وهذا إسناد ضعيف، ابن لهيعة سيء الحفظ، وأبو الزبير رمي بالتدليس