Sahih Bukhari
Beginning of Creation
Volume: 004 / Book Number: 054 / Hadith Number: 522
Narrated Abu Huraira:
The Prophet said, "When you hear the crowing of cocks, ask for Allah's Blessings for (their crowing indicates that) they have seen an angel. And when you hear the braying of donkeys, seek Refuge with Allah from Satan for (their braying indicates) that they have seen a Satan."