It is narrated from Abdullah bin Dinar (may Allah have mercy on him) that when Abdullah bin Umar (may Allah be pleased with them both) pledged allegiance to Abdul Malik bin Marwan, he wrote to him: «بسم الله الرحمن الرحیم» , From Abdullah bin Umar to the Commander of the Faithful, Abdul Malik. Peace be upon you. I praise Allah, Who has no partner, and I acknowledge that, to the best of my ability, I will listen to your commands and obey, as long as they are in accordance with what Allah Almighty and His Messenger (peace and blessings be upon him) have prescribed.