It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that Sayyiduna al-Bara' bin Ma'rur (may Allah be pleased with him) was the first person to pledge allegiance at the hand of the Messenger of Allah (peace and blessings be upon him) on the Night of Aqabah, in the presence of seventy men of the Ansar. Al-Bara' bin Ma'rur stood up, praised and extolled Allah, and then said: "All praise is for Allah, who honoured us through Muhammad (peace and blessings be upon him) and granted him (peace and blessings be upon him) to us (as a guide). We were the first to answer the call of the caller and the last to be called. We accepted the call of Allah, the Mighty and Majestic, and showed hearing and obedience. O assembly of the Aws and the Khazraj, Allah Almighty has indeed honoured you with His religion. So if you pledge hearing, obedience and support with gratitude, then obey Allah and His Messenger." Then he sat down. This hadith has a sahih (authentic) chain of narration, and the two Shaykhs did not record it.