Narrated from Sayyiduna Abu Sa‘id Khudri (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said: "When you hear the call to prayer (adhan), then say as the muezzin says."

`Sayyiduna Amir Muawiyah (may Allah be pleased with him) responded to the adhan up to "Ashhadu anna Muhammadan Rasulullah" just as the adhan is said, and when (the muezzin said) "Hayya 'ala-s-Salah," he said "La hawla wa la quwwata illa billah," and said that I heard the Noble Prophet (peace and blessings of Allah be upon him) saying it in this manner.