Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) taught us the tashahhud: "All reverences, prayers and pure words are for Allah alone. O Prophet, peace be upon you, and the mercy of Allah and His blessings. Peace be upon us and upon the righteous servants of Allah. I bear witness that there is no deity except Allah, and I bear witness that Muhammad (peace and blessings be upon him) is His servant and His Messenger." (Imam al-Tabarani said:) Al-Ajlah narrated it as marfu' (attributed to the Prophet), while Hammad bin Salamah did not narrate it as marfu'.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 9903