Sahih al-Bukhari 3081

Narrated Sa`d bin 'Ubaida:Abu `Abdur-Rahman who was one of the supporters of `Uthman said to Abu Talha who was one of the supporters of `Ali, "I perfectly know what encouraged your leader (i.e. `Ali) to shed blood. I heard him saying: Once the Prophet (ﷺ) sent me and Az-Zubair saying, 'Proceed to such-and-such Ar-Roudah (place) where you will find a lady whom Hatib has given a letter. So when we arrived at Ar-Roudah, we requested the lady to hand over the letter to us. She said, 'Hatib has not given me any letter.' We said to her. 'Take out the letter or else we will strip off your clothes.' So she took it out of her braid. So the Prophet (ﷺ) sent for Hatib, (who came) and said, 'Don't hurry in judging me, for, by Allah, I have not become a disbeliever, and my love to Islam is increasing. (The reason for writing this letter was) that there is none of your companions but has relatives in Mecca who look after their families and property, while I have nobody there, so I wanted to do them some favor (so that they might look after my family and property).' The Prophet (ﷺ) believed him. `Umar said, 'Allow me to chop off his (i.e. Hatib's) neck as he has done hypocrisy.' The Prophet (ﷺ) said, (to `Umar), 'Who knows, perhaps Allah has looked at the warriors of Badr and said (to them), 'Do whatever you like, for I have forgiven you.' " `Abdur-Rahman added, "So this is what encouraged him (i.e. `Ali).