Al-Madinah eliminates its Dross and it is also called Tabah, and Taibah Sahih Muslim 1384
Arabic hadith text
وَحَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ مُعَاذٍ، - وَهُوَ الْعَنْبَرِيُّ - حَدَّثَنَا أَبِي، حَدَّثَنَا شُعْبَةُ، عَنْ عَدِيٍّ، - وَهُوَ ابْنُ ثَابِتٍ - سَمِعَ عَبْدَ اللَّهِ بْنَ يَزِيدَ، عَنْ زَيْدِ بْنِ ثَابِتٍ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ "إِنَّهَا طَيْبَةُ - يَعْنِي الْمَدِينَةَ - وَإِنَّهَا تَنْفِي الْخَبَثَ كَمَا تَنْفِي النَّارُ خَبَثَ الْفِضَّةِ" .
Translation
Zaid b. Thabit reported Allah's Apostle (ﷺ) as saying
It is Taiba, thereby meaning Medina. It drives away impurity just as fire removes the impurity of silver.