It is narrated from Sayyiduna Usayd bin Hudayr (may Allah be pleased with him) that he said: O Messenger of Allah! I was reciting Surah al-Baqarah when I heard a sound behind me, and I thought that my horse had broken loose. The Messenger of Allah (peace and blessings be upon him) said: "O Abu Atik! Keep reciting." He said: I turned around and saw lamps hanging between the heaven and the earth, while the Messenger of Allah (peace and blessings be upon him) was saying: "O Abu Atik! Keep reciting." He said: O Messenger of Allah! I did not have the strength to continue. He (peace and blessings be upon him) said: "Those were the angels who descended for the recitation of Surah al-Baqarah. Indeed, had you continued, you would have seen wonders."
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 562