Sayyiduna Abdullah bin Mughaffal (may Allah be pleased with him) narrates: I was one of those people whom Allah Almighty has mentioned (in this verse) (the saying of the Exalted): "I do not find (an extra animal) to give you to ride on." He said: I was holding the branches of the tree under which the Prophet (peace and blessings be upon him) was taking the pledge from the people; I was shading him. The narrator says: We pledged allegiance to him on the condition that we would not flee.
Al-Tabarani recorded it. Its chain is jayyid (good), except that al-Rabi' bin Anas stated that it is narrated from Abu al-Aliyah or from someone other than him.