Mishkat al-Masabih 4 Prayer كتاب الصلاة 100

وَعَنْ عُثْمَانَ بْنِ أَبِي الْعَاصِ قَالَ قُلْتُ: يَا رَسُول الله اجْعَلنِي إِمَام قومِي فَقَالَ: «أَنْتَ إِمَامُهُمْ وَاقْتَدِ بِأَضْعَفِهِمْ وَاتَّخِذْ مُؤَذِّنًا لَا يَأْخُذُ عَلَى أَذَانِهِ أَجْرًا» . رَوَاهُ أَحْمَدُ وَأَبُو دَاوُد وَالنَّسَائِيّ

‘Uthman b. Abul ‘As said that he asked God’s Messenger to make him his people’s imam and that he replied, “You are their imam , but do according to what the weakest of them is capable of, and employ a mu’adhdhin who does not accept payment for his adhan .” Ahmad, Abu Dawud and Nasa’i transmitted it.