Mukhtasar Muslim

It is narrated from Amir al-Mu'minin Sayyiduna Ali (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) sent an army and appointed a man as their leader (amir). He lit a fire and told the people to enter it. Some people intended to enter it, while others said, "We became Muslims by fleeing from the fire (and we abandoned disbelief out of fear of Hell, so how can we now enter the fire again? This is not possible for us)." Then this matter was mentioned to the Messenger of Allah (peace and blessings be upon him), and he said to those who intended to enter, "If you had entered it, you would have remained in it forever (because this is suicide and forbidden in Shariah)." And he praised those who were not willing to enter and said, "There is no obedience to anyone in disobedience to Allah; rather, obedience is only in what is permissible."