القرآن المبين

سورة لقمان · 31:19

وَاقْصِدْ فِي مَشْيِكَ وَاغْضُضْ مِنْ صَوْتِكَ ۚ إِنَّ أَنْكَرَ الْأَصْوَاتِ لَصَوْتُ الْحَمِيرِ

Be moderate in your pace. And lower your voice, for the ugliest of all voices is certainly the braying of donkeys.”