It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that I heard the Prophet (peace and blessings of Allah be upon him) saying: "May Allah keep the tribe of Aslam safe, and may Allah forgive the tribe of Ghifar."
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 6040