Sahih Bukhari | Volume 5 | Hadith Number 195

Narrated by 'Urwa bin Az-Zubair
I asked Ibn Amr bin Al-As, "Tell me of the worst thing which the pagans did to the Prophet." He said, "While the Prophet was praying in the Hijr of the Ka'ba; 'Uqba bin Abi Mu'ait came and put his garment around the Prophet's neck and throttled him violently. Abu Bakr came and caught him by his shoulder and pushed him away from the Prophet and said, "Do you want to kill a man just because he says, 'My Lord is Allah?' "