Musnad Ahmad 32:380

Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, he said: I heard Qatadah narrating from Anas ibn Malik, he said: The Messenger of Allah (peace and blessings of Allah be upon him) said to Ubayy ibn Ka'b: "Indeed, Allah has commanded me to recite to you: {Those who disbelieved...} [Al-Bayyinah: 1]." He said: "And did He name me to you?" He said: "Yes." So he wept.