Volume 9, Book 89, Number 318:
Narrated Jabir bin ‘Abdullah:
A bedouin gave the Pledge of allegiance to Allah’s Apostle for Islam. Then the bedouin got fever at
Medina, came to Allah’s Apostle and said, “O Allah’s Apostle! Cancel my Pledge,” But Allah’s Apostle
refused. Then he came to him (again) and said, “O Allah’s Apostle! Cancel my Pledge.” But the Proph –
et refused Then he came to him (again) and said, “O Allah’s Apostle! Cancel my Pledge.” But the
Prophet refused. The bedouin finally went out (of Medina) whereupon Allah’s Apostle said, “Medina
is like a pair of bellows (furnace): It expels its impurities and brightens and clears its good.