It is narrated from Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Do not harm anyone, and do not harm anyone in retaliation. Whoever harms someone, Allah will harm him; and whoever stirs up discord, Allah will stir up discord against him."
Uthman bin Muhammad alone narrated it from al-Darawardi.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلح / 11384