Musannaf Ibn Abi Shayba 27:63

Mu'awiyah ibn Hisham narrated to us, he said: 'Ammar ibn Ruzayq narrated to us, from 'Abdullah ibn 'Isa, from Sa'id ibn Jubayr, from Ibn 'Abbas, who said: While Jibril was sitting with the Messenger of Allah (may Allah bless him and grant him peace), he heard a creaking sound from above him. He raised his head and said: "A gate of the heaven has been opened today that has never been opened before." Then an angel came to him and said: "Receive glad tidings of two lights that you have been given, which no one before you was given: the Opening of the Book (Al-Fatiha) and the concluding verses of Surat Al-Baqarah. You will not recite a single letter from them except that you will be granted it."