This hadith has been narrated by Yabya b. Sa'id with the same chain of transmitters (and the words are):" Just as a furance removes impurity," but no mention is made of iron
Hadith 3355 — Sahih Muslim 15:559
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، قَالَ قَرَأْتُ عَلَى مَالِكٍ عَنْ مُحَمَّدِ بْنِ الْمُنْكَدِرِ، عَنْ جَابِرِ، بْنِ عَبْدِ اللَّهِ أَنَّ أَعْرَابِيًّا، بَايَعَ رَسُولَ اللَّهِ صلى الله عليه وسلم فَأَصَابَ الأَعْرَابِيَّ وَعَكٌ بِالْمَدِينَةِ فَأَتَى النَّبِيَّ صلى الله عليه وسلم فَقَالَ يَا مُحَمَّدُ أَقِلْنِي بَيْعَتِي . فَأَبَى رَسُولُ اللَّهِ صلى الله عليه وسلم ثُمَّ جَاءَهُ فَقَالَ أَقِلْنِي بَيْعَتِي . فَأَبَى ثُمَّ جَاءَهُ فَقَالَ أَقِلْنِي بَيْعَتِي . فَأَبَى فَخَرَجَ الأَعْرَابِيُّ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِنَّمَا الْمَدِينَةُ كَالْكِيرِ تَنْفِي خَبَثَهَا وَيَنْصَعُ طَيِّبُهَا " .
Jabir b. `Abdullah (Allah be pleased with them) reported that a desert Arab swore allegiance to Allah's Messenger (ﷺ). He suffered from a severe fever in Medina (and) so he came to Allah's Messenger (ﷺ) saying:Muhammad, cancel my oath of allegiance. But Allah's Messenger (ﷺ) refused it. He again came and said: Cancel my oath of allegiance. But he (the Holy Prophet) refused it. He again came to him and said: Cancel my oath of allegiance, but he refused. The desert Arab, however, went away (cancelling the allegiance himself). Thereupon Allah's Messenger (ﷺ) said: Medina is like a furnace which drives away its impurity and purifies what is good
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
Abu Huraira (Allah be pleased with him) reported that Abul-Qasim (Muhammad, may peace be upon him) said:He who intends to do harm to the people of this city (that is, Medina), Allah would efface him as salt is dissolved in water
Abu Huraira reported Allah's Messenger (ﷺ) as saying:He who intends to do harm to its people (he meant Medina), Allah would efface him as salt is dissolved in water. Ibn Hatim (one of the narrators) substituted the word" harm" for" mischief
Sa'd b. Abu Waqqas reported Allah's Messenger (ﷺ) as saying:He who intends to do harm to the people of Medina, Allah would efface him just as water dissolves salt
Abu Huraira and Sa'd reported Allah's Messenger (way peace be upon him) as saying:O Allah, bless the people of Medina in their mudd, the rest of the hadith being the same, and in It (this is also mentioned):" He wo intends to do harm to its people, Allah would efface him just as salt it dissolved in water