وَاقْصِدْ فِي مَشْيِكَ وَاغْضُضْ مِنْ صَوْتِكَ ۚ إِنَّ أَنْكَرَ الْأَصْوَاتِ لَصَوْتُ الْحَمِيرِ 19
And be moderate in your pace and lower your voice; indeed, the most disagreeable of sounds is the voice of donkeys."