The tribe of Banu Amir ibn Sa'sa'ah had been responsible for the massacre of Muslims at Bi'r Ma'una. They sent a delegation to Madinah, probably in the 7th or 8th year of the Hijrah, before the Conquest of Makkah. With them came Amir ibn al-Tufayl, one of the chief instigators of that massacre. He had no intention of becoming a Muslim.
Amir made a plan with his henchman Arbad ibn Qays to kill the Prophet ﷺ. Amir would distract him with questions, and when Amir gave a secret signal, Arbad would stab him, most likely with a poisoned dagger. Amir asked the Prophet ﷺ for a private audience, but the Prophet ﷺ refused unless Amir first embraced Islam. Amir gave the signal three times, and each time Arbad did nothing. Arbad later explained that whenever the signal came, he could see only Amir and not the Prophet ﷺ.
When Amir saw that the plot had failed, he offered the Prophet ﷺ three choices. The first was to split the leadership, with the Prophet ﷺ ruling the townspeople and Amir ruling the Bedouins. The second was to name Amir as his successor. Otherwise, Amir would bring an army of a thousand male and a thousand female camels against him. The Prophet ﷺ refused all three. He said, "O Allah, I put You in charge of being sufficient for me against Amir ibn al-Tufayl. O Allah, take care of him and guide his people."
Both men met a grim end. On the way home, Amir spent the night at the house of a prostitute and was struck there by a fatal illness. Not wanting to die in such a house, he rode off on his horse into the darkness and was never seen again. Arbad returned to his tribe and said something blasphemous about Allah. The next day, in front of his people, lightning struck and killed both him and his camel. It is said that Qur'an 13:11-13 refers to his fate.