It is narrated from Mahmud bin Ali al-Qurazi (may Allah have mercy on him) that when the mu'adhdhin called the adhan, Mu'awiyah bin Abi Sufyan (may Allah be pleased with him) said the takbir just as he did and bore witness just as he did. When he said: "Hayya 'ala al-salah, hayya 'ala al-falah" (Come to prayer, come to success), he said: "La hawla wa la quwwata illa billah (There is no power to avoid sin nor strength to do good except through Allah's help). This is how I heard the Messenger of Allah (peace and blessings be upon him) say it."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 16842