The supplication the Prophet (peace and blessings be upon him) commanded Umar bin al-Khattab to make

Ibn Ukaym said: Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) said to me that the Messenger of Allah (peace and blessings be upon him) had said to him: "O son of al-Khattab, say: O Allah, make my inner self better than my outward self, and make my outward self righteous."

Urwah bin al-Zubayr said: The supplication of the Prophet (peace and blessings be upon him) was like this: "O Allah, help me to remember You, to give thanks to You, and to worship You well."