once
إِذَا سَمِعْتُمْ نُبَاحَ الْكِلاَبِ وَنَهِيقَ الْحَمِيرِ بِاللَّيْلِ فَتَعَوَّذُوا بِاللَّهِ مِنْهُنَّ؛ فَإِنَّهُنَّ يَرَيْنَ مَا لاَ تَرَوْنَ
Meaning
If you hear the barking of dogs or the braying of asses at night, seek refuge in Allah for they see what you do not.
Source and references
Hisn al-Muslim, entry 229.The reference is copied from the edition; separate editorial verification is not complete yet.
Source edition: Fortress of the Muslim. Open source ↗