Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) narrates: Hatib bin Abi Balta'ah (may Allah be pleased with him) wrote a letter to the people of Makkah. Allah Almighty informed His Prophet of it, and the Prophet (peace and blessings be upon him) sent Ali and al-Zubayr after that letter. The two of them reached a woman who was riding a camel; they had the letter taken out from her hair and brought it to the Prophet (peace and blessings be upon him). The letter was read out before the Prophet (peace and blessings be upon him). The Prophet (peace and blessings be upon him) summoned Hatib and asked: O Hatib! Did you write this letter? He replied: Yes! The Prophet (peace and blessings be upon him) asked: Why did you do this? He replied: O Messenger of Allah! By Allah! I am a well-wisher of Allah and His Messenger (peace and blessings be upon him), but I was a stranger in Makkah, and my family are among those people. I feared for that family, so I wrote a letter that could not harm Allah and His Messenger (peace and blessings be upon him) in any way, but it might have become a source of benefit for my family. Sayyiduna Umar (may Allah be pleased with him) narrates: I drew my sword and then submitted: O Messenger of Allah! Allow me to kill Hatib, for he has committed disbelief. The Prophet (peace and blessings be upon him) said: O Ibn al-Khattab! What do you know? Perhaps Allah Almighty looked upon this group of the people of Badr and then said: "Do whatever you wish; I have forgiven you."
Abu Ya'la recorded it in al-Kabir, and al-Bazzar and al-Tabarani in al-Mu'jam al-Awsat recorded it in abridged form, and their narrators are the narrators of the Sahih.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب المناقب / 15662