Musannaf Ibn Abi Shaybah

Hazrat Hafsa narrates that when my father Sirin got married, he hosted a feast for seven days for the companions of the Messenger of Allah, peace be upon him. When it was the day of the Ansar's invitation, Hazrat Ubayy bin Ka'b, Hazrat Zaid bin Thabit, and Hazrat Mu'adh, may Allah be pleased with them, were invited. Hazrat Ubayy, may Allah be pleased with him, was fasting that day. When everyone had finished eating, Hazrat Ubayy, may Allah be pleased with him, made a supplication and the rest of the people said Ameen to that supplication.