Malik related to me from Abdullah ibn Dinar that Abdullah ibnUmar wrote to Abd al-Malik ibn Marwan, making an oath of allegiance.He wrote, "In the name of Allah, the Merciful, the Compassionate. Tothe slave of Allah, Abd al-Malik, the amir al-muminin, Peace be uponyou. I praise Allah to you. There is no god but Him. I acknowledgeyour right to my hearing and my obedience according to the sunna ofAllah and the sunna of His Prophet, in what I am able."
USC-MSA web (English) reference: Book 55, Hadith 3
Arabic reference: Book 55, Hadith 1813