Mukhtasar Muslim

Narrated from Sayyiduna Abu Huraira (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said: A time will come upon the people when a man will call his nephew and his close relative, saying, "Come to prosperity, come to prosperity," although Medina will be better for them if they only knew. And by the One in Whose hand is my soul, no one leaves Medina out of aversion to it except that Allah brings someone better than him to reside in Medina. Be aware that Medina is like a blacksmith's furnace; it removes impurities. And the Hour will not be established until Medina expels its wicked people just as a furnace removes the impurities of iron.