It is narrated from Sayyiduna Ka'b bin Malik (may Allah be pleased with him), who was one of the three whose repentance was accepted, that the Prophet (peace and blessings be upon him) stood up to deliver a sermon. He praised and extolled Allah and sought forgiveness for those martyred on the day of Uhud, then said: "O company of the Muhajirun! You are increasing, while the Ansar are not increasing. The Ansar are my confidants with whom I take refuge, so honour the noble among them and overlook those of them who do wrong."
Hadith Referenceالمعجم الكبير للطبراني / باب الكاف / 16209