Musnad Ahmad 28:125

Hassan narrated to us, Ibn Lahi'ah narrated to us, Huyayy ibn Abdullah narrated to us, that Abu Abd al-Rahman al-Hubuli narrated to him, from Abdullah ibn Amr, that a man said to the Messenger of Allah, may Allah bless him and grant him peace: "O Messenger of Allah, the mu'adhdhins (callers to prayer) surpass us with their adhan." The Messenger of Allah, may Allah bless him and grant him peace, said to him: "Say as they say, and when you finish, ask, and you shall be given."