حِصْنُ الْمُسْلِمِ
Hisn al-Muslim 228
Fortress of the Muslim (Hisn al-Muslim)
Upon hearing a rooster crow or the braying of a donkey
إِذَا سَمِعْتُمْ صِيَاحَ الدِّيَكَةِ فَاسْأَلُوا اللَّهَ مِنْ فَضْلِهِ؛ فَإِنَّهَا رَأَتْ مَلَكاً وَإِذَا سَمِعْتُمْ نَهِيقَ الْحِمَارِ فَتَعَوَّذُوا بِاللَّهِ مِنَ الشَّيطَانِ؛ فَإِنَّهُ رَأَى شَيْطَاناً
-- When you hear the cock's crow, ask Allah for His favor upon you for surely it has seen an angel. When you hear the bray of a donkey, seek refuge in Allah from Satan, for surely it has seen a devil. Reference: Al-Bukhari, cf. Al-Asqalani, Fathul-Bari 6/350, Muslim 4/2092.
Hisn al-Muslim, 228