Musnad Ahmad 1060:46

Yazid narrated to us, Abu Malik—meaning al-Ashja‘i—narrated to us, Musa ibn Talhah narrated to us, from Abu Ayyub al-Ansari, from the Prophet, peace and blessings of Allah be upon him, who said: "Indeed, Aslam, Ghifar, Muzaynah, Ashja‘, and Juhaynah, and whoever among the Banu Ka‘b are allies, to the exclusion of other people, and Allah and His Messenger are their allies."