Sahih Muslim, 3355

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

Rapporté par Jabir ibn 'Abdullah رضي الله عنه : Un Bédouin prêta serment d’allégeance au Messager d’Allah ﷺ. Il souffrit d’une forte fièvre à Médine et vint voir le Prophète ﷺ en disant : « Muhammad, annule mon serment d’allégeance. » Mais le Messager d’Allah ﷺ refusa. Il revint encore demander l’annulation, mais le Prophète ﷺ refusa à chaque fois. Finalement, le Bédouin partit de lui-même. Le Messager d’Allah ﷺ dit alors : « Médine est comme un four : elle chasse ses impuretés et purifie ce qui est bon. »