Abu Wa'il says that when Sayyiduna Ibn Mas'ud (may Allah be pleased with him) killed Ibn Nawahah, he said: "This man and Ibn Athal had come to the Prophet (peace be upon him) as messengers from Musaylimah the Liar. The Prophet (peace be upon him) asked both of them: 'Do you both testify that I am the Messenger of Allah?' They said, 'We testify that Musaylimah is the Messenger of Allah.' The Prophet (peace be upon him) said: 'If I were to kill messengers, I would have beheaded both of you.' From that time, it became customary that messengers are not killed. In any case, Allah sufficed us concerning Ibn Athal (he died), and this man remained as he was, until now Allah has given us power over him."