HAKIM 6194:
from Fityah Saʾalūā Abū Usayd al-Sāʿidī —
[Machine] On the occasion of the Prophet Muhammad's choosing the Ansar, he said, "I heard the Messenger of Allah, peace be upon him, saying: 'The best of the Ansar tribes are the Daws tribe, then the Banu Abd al-Ashhal tribe, then the Banu Harith bin Khazraj tribe, then the Banu Sa'idah tribe. And in every tribe of the Ansar, there is goodness.' Abu Usaid said, 'If I had to meet someone other than the truth, I would begin with the Banu Sa'idah tribe by my thigh.'"
الحاكم ٦١٩٤:
عن فتيه سءلوا ابو اسيد الساعدي —
عَنْ تَخْيِيرِ رَسُولِ اللَّهِ ﷺ الْأَنْصَارَ فَقَالَ سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ خَيْرُ قَبَائِلِ الْأَنْصَارِ دُورُ بَنِي النَّجَّارِ ثُمَّ بَنِي عَبْدِ الْأَشْهَلِ ثُمَّ بَنِي الْحَارِثِ بْنِ الْخَزْرَجِ ثُمَّ بَنِي سَاعِدَةَ وَفِي كُلِّ دُورِ الْأَنْصَارِ خَيْرٌ قَالَ أَبُو أُسَيْدٍ «لَوْ كُنْتُ قَابِلًا غَيْرَ الْحَقِّ لَبَدَأْتُ بِفَخِذِي بَنُو سَاعِدَةَ»
hadithunlocked.com