Al-Bukhari recorded from `Abdullah - that is Ibn Mas`ud -- that he said, "While we were with the Messenger of Allah in a cave at Mina,
(By the Mursalat.) was revealed to him. He was reciting it and I was learning it from his mouth. Verily, his mouth was moist with it when a snake leaped out at us. The Prophet said,
(Kill it!) So we quickly went after it, but it got away. Then the Prophet said,
(It was saved from your harm just as you all were saved from its harm.)'' Muslim also recorded this Hadith by way of Al-A`mash. Imam Ahmad recorded from Ibn `Abbas, who reported from his mother that she heard the Prophet reciting
(By the Mursalat.) in the Maghrib prayer. In a report from Malik on the authority of Ibn `Abbas, he narrated that Umm Al-Fadl (his mother) heard him (Ibn `Abbas) reciting
(By the Mursalat `Urfa.) (77:1) so she said, "O my son! You reminded me with your recitation of this Surat. Verily, it is the last thing I heard from the Messenger of Allah . He recited it in the Maghrib prayer (i.e., before he died).'' Both Al-Bukhari and Muslim recorded this report in the Two Sahihs by way of Malik.
In the Name of Allah, the Most Gracious, the Most Merciful.