Musnad Abu Ya'la al-Mawsili 42:234

Narrated to us Zuhayr, narrated to us Abu Mu'awiyah, narrated to us al-A'mash, from Abu Salih, from Abu Sa'id, from the Prophet (peace be upon him), regarding His saying: "And thus We have made you a just community" (Al-Baqarah). He said: "Just."