Abu Huraira (Allah be pleased with him) reported Allah’s Messenger (ﷺ) as saying:
A time will come for the people (of Madina) when a man will invite his cousin and any other near relation: Come to prosperity, come to prosperity, but Medina will be better for them; would they know it! By Him in Whose Hand is my soul, none amongst them would leave (the city) with a dislike for it, but Allah would replace him with someone better than he. Indeed Madina drives out its evils. And the Hour will not come until Medina eliminates its evils just as a furnace eliminates the impurities of iron.
حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا عَبْدُ الْعَزِيزِ، – يَعْنِي الدَّرَاوَرْدِيَّ – عَنِ الْعَلاَءِ، عَنْ أَبِيهِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ “ يَأْتِي عَلَى النَّاسِ زَمَانٌ يَدْعُو الرَّجُلُ ابْنَ عَمِّهِ وَقَرِيبَهُ هَلُمَّ إِلَى الرَّخَاءِ هَلُمَّ إِلَى الرَّخَاءِ وَالْمَدِينَةُ خَيْرٌ لَهُمْ لَوْ كَانُوا يَعْلَمُونَ وَالَّذِي نَفْسِي بِيَدِهِ لاَ يَخْرُجُ مِنْهُمْ أَحَدٌ رَغْبَةً عَنْهَا إِلاَّ أَخْلَفَ اللَّهُ فِيهَا خَيْرًا مِنْهُ أَلاَ إِنَّ الْمَدِينَةَ كَالْكِيرِ تُخْرِجُ الْخَبِيثَ . لاَ تَقُومُ السَّاعَةُ حَتَّى تَنْفِيَ الْمَدِينَةُ شِرَارَهَا كَمَا يَنْفِي الْكِيرُ خَبَثَ الْحَدِيدِ ” .
Reference : Sahih Muslim 1381
In-book reference : Book 15, Hadith 556
USC-MSA web (English) reference : Book 7, Hadith 3188