Musannaf Ibn Abi Shayba 2:4

Abu Bakr narrated to us, he said: Ibn ‘Ulayyah narrated to us, from Ibn ‘Awn, from Muhammad, who said: The Adhan was that one says: Allah is the Greatest, Allah is the Greatest; I bear witness that there is no god but Allah, I bear witness that there is no god but Allah; I bear witness that Muhammad is the Messenger of Allah, I bear witness that Muhammad is the Messenger of Allah; come to prayer, come to prayer; come to success, come to success; Allah is the Greatest, Allah is the Greatest; there is no god but Allah.