Sahih al-Bukhari 1871
Book 29: Virtues of Madinah · Narrated by Abu Huraira
Arabic
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، أَخْبَرَنَا مَالِكٌ، عَنْ يَحْيَى بْنِ سَعِيدٍ، قَالَ سَمِعْتُ أَبَا الْحُبَابِ، سَعِيدَ بْنَ يَسَارٍ يَقُولُ سَمِعْتُ أَبَا هُرَيْرَةَ ـ رضى الله عنه ـ يَقُولُ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم. " أُمِرْتُ بِقَرْيَةٍ تَأْكُلُ الْقُرَى يَقُولُونَ يَثْرِبُ. وَهْىَ الْمَدِينَةُ، تَنْفِي النَّاسَ كَمَا يَنْفِي الْكِيرُ خَبَثَ الْحَدِيدِ ".
English translation
Narrated Abu Huraira:Allah's Messenger (ﷺ) said, "I was ordered to migrate to a town which will swallow (conquer) other towns and is called Yathrib and that is Medina, and it turns out (bad) persons as a furnace removes the impurities of iron
Reference: Sahih al-Bukhari 1871, Book of Virtues of Madinah. English translation by Dr. Muhammad Muhsin Khan.