Sayyiduna Ma'qil bin Sinan (may Allah be pleased with him) reports this saying of the Prophet (peace and blessings be upon him): "Ghifar, Aslam, Juhaynah and Muzaynah (the people of these tribes) are the mawali (that is, companions) of Allah Almighty and His Messenger."
Al-Tabarani recorded it, and its chain is hasan (good).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب المناقب / 16557