Musnad Ahmad 161:2

Ya'mar ibn Bishr narrated to us, Abdullah narrated to us, he said: Yunus informed us, from al-Zuhri, he said: I heard Sinan ibn Abi Sinan, he said: I heard Abu Hurayrah saying while standing in his storytelling: "Indeed, a brother of yours used to not say obscenity — meaning Ibn Rawahah — he said: And among us is the Messenger of Allah, reciting His Book, When a light breaks forth from the night, shining. He spends the night keeping his side away from his bed, When the beds become heavy for the disbelievers. He showed us guidance after blindness, so our hearts, Because of him, are certain that what he said is reality."