It is narrated from Sayyiduna Uthman bin Abi al-As (may Allah be pleased with him) that he said: I said: O Messenger of Allah, make me the imam of my people. He (peace and blessings be upon him) said: "You are their imam, so have regard for the weakest of them, and appoint a muezzin who does not take a wage for his adhan."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2018