Sunan Abi Dawud Book 2, Hadith 140
The Messenger of Allah (ﷺ) taught me to say when the adhan for the sunset prayer was called; "O Allah, this is the time when Thy night comes on, Thy day retires, and the voices of Thy summoners are heard, so forgive me."
if anyone says when he hears the call to prayer : “O Allah, Lord of this perfect call and of the prayer which is established for all time, grant Muhammad the wasilah and excellency, and raise him up in a praiseworthy position which Thou hast promised, he will be assured of my intercession.
Messenger of Allah, appoint me the leader of the tribe in prayer. He said: You are their leader, but you should follow on who is the weakest of them: and appoint a mu'adhdhin who does not charge for the calling of adhan.