It is narrated from Abu Salamah bin Abd al-Rahman bin Awf (may Allah have mercy on him) that Abu Usayd (may Allah be pleased with him), the Companion of the Prophet (peace and blessings be upon him), told him: I heard the Prophet (peace and blessings be upon him) say: "The best of the households of the Ansar are the households of Banu al-Najjar, then Banu Abd al-Ashhal, then the household of al-Harith bin al-Khazraj, then the household of Banu Sa'idah; and in every household of the Ansar there is good." Abu Usayd said: "If I were a liar, I would have begun with my own people, Banu Sa'idah." This reached Sa'd bin Ubadah and he felt aggrieved by it, and said: We were created as the most important of the four. Saddle my donkey for me; I am going to the Messenger of Allah (peace and blessings be upon him). His nephew Sahl said to him: Are you going to dispute the word of the Messenger of Allah (peace and blessings be upon him), when Allah and His Messenger know best? So he ordered that his donkey be unsaddled.
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 16638