Musnad Ahmad 936:10

Abdullah narrated to us, Mus’ab ibn Abdullah al-Zubayri narrated to me, Abd al-Aziz ibn Muhammad narrated to us, from Sharik ibn Abdullah ibn Abi Namir, from Ata ibn Yasar, from Ubayy ibn Ka’b: That the Messenger of Allah (peace and blessings of Allah be upon him) recited *Bara’ah* (Surah al-Tawbah) on the day of Friday while he was standing, reminding [the people] of the days of Allah. Ubayy ibn Ka’b was facing the Prophet (peace and blessings of Allah be upon him), and [so were] Abu al-Darda’ and Abu Dharr. Ubayy ibn Ka’b nudged one of them and said: "When was this Surah revealed, O Ubayy? For I have not heard it until now." He signaled to him to be silent. When they finished, he said: "I asked you when this Surah was revealed, and you did not inform me." Ubayy said: "You have nothing from your prayer today except what you spoke in vain." So he went to the Messenger of Allah (peace and blessings of Allah be upon him) and mentioned that to him, and informed him of what Ubayy had said. He said: "Ubayy spoke the truth."