Musnad Ahmad 435:1

Isma'il ibn Ibrahim narrated to us, Hisham al-Dastawa'i informed us, my father said: And Abu 'Amir al-'Aqadi said: Hisham narrated to us, from Yahya ibn Abi Kathir, from Muhammad ibn Ibrahim, from 'Isa ibn Talhah. Abu 'Amir said in his narration: 'Isa ibn Talhah narrated to me, he said: We entered upon Mu'awiyah, and the caller called for the prayer. He said: "Allah is the Greatest, Allah is the Greatest." Mu'awiyah said: "Allah is the Greatest, Allah is the Greatest." He said: "I bear witness that there is no god but Allah." Mu'awiyah said: "And I bear witness" — Abu 'Amir said: "that there is no god but Allah." He said: "I bear witness that Muhammad is the Messenger of Allah." Mu'awiyah said: "And I bear witness" — Abu 'Amir said: "that Muhammad is the Messenger of Allah." Yahya said: A man narrated to us that when he said: "Come to prayer," he said: "There is no power and no strength except by Allah." Mu'awiyah said: "Thus I heard your Prophet, may Allah bless him and grant him peace, say."