A man reviled Abu Bakr (may Allah be pleased with him), and the narrator said: Shall I not kill him, O successor of the Messenger of Allah? Abu Bakr (may Allah be pleased with him) said: This is not befitting for anyone after the Prophet (peace and blessings be upon him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13377