Sahih Bukhari Volume 6, Book 60, Hadith Number 452.

Narrated By Abdullah : We were with the Prophet when Surat Wal-Mursalat was revealed to him. While we were receiving it from his mouth, a snake suddenly came and we ran to kill it, but it outstripped us and entered its hole quickly. Allah’s le said, “It has escaped your evil, and you too, have escaped its evil.”