Musannaf Ibn Abi Shayba 22:224

Affan narrated to us, he said: Hammad bin Salamah narrated to us, from Ali bin Zaid, from Ammar bin Abi Ammar, he said: I heard Abu Habba al-Badri say: When "Those who disbelieved among the People of the Scripture..." (to the end of it) was revealed, Gabriel said: "O Messenger of Allah, your Lord commands you to have Ubayy recite it." The Prophet, may Allah bless him and grant him peace, said to Ubayy: "Gabriel commanded me to have you recite this surah." Ubayy said: "Did he mention me, O Messenger of Allah?" He said: "Yes."