Silsilat al-Ahadith al-Sahihah

The Messenger of Allah (peace and blessings be upon him) said: "This (i.e., Madinah) is Tayyibah; it expels (the filth of sins) just as fire removes the impurities from silver." This hadith is narrated from Sayyiduna Zayd bin Thabit, Sayyiduna Abu Hurairah, Sayyiduna Jabir, Sayyiduna Abu Umamah, and Sayyiduna Abu Qatadah (may Allah be pleased with them).