Urwah narrates: Sayyiduna al-Abbas (may Allah be pleased with him) said: By Allah! When the seventy men of the Ansar came on the night of the Pledge of al-Aqabah, Sayyiduna al-Abbas (may Allah be pleased with him) took hold of the hand of the Prophet (peace and blessings be upon him) and settled the conditions with them on behalf of the Prophet (peace and blessings be upon him). This was in the early period of Islam, before anyone worshipped Allah Almighty openly.
Abu Ya'la recorded it in the middle of a hadith narrated by Sayyidah Aishah (may Allah be pleased with her); its chain contains a narrator, Abd al-Rahman bin Abi al-Zinad, who is da'if (weak).