Narrated Jabir:that a Bedouin gave the pledge to the Messenger of Allah (ﷺ) for Islam, then he was afflicted by the sickness in Al-Madinah. So the Bedouin went to the Messenger of Allah (ﷺ) and said: "Take back my pledge." But the Messenger of Allah (ﷺ) refused. Then the Bedouin left and came back and said: "Take back my pledge," and he refused. Then the Messenger of Allah (ﷺ) said: "Al-Madinah is but like bellows, it expels its filth and purifies its good

English translation · Jami' at-Tirmidhi