Amr bin Shu`aib narrated from his father, from his grandfather, that the Prophet (ﷺ) said:
“The best of supplication is the supplication of the Day of `Arafah. And the best of what I and the Prophets before me have said is: None has the right to be worshipped but Allah, Alone, without partner, to Him belongs all that exists, and to Him belongs the Praise, and He is powerful over all things. (Lā ilāha illallāh, waḥdahu lā sharīka lahu, lahul-mulku wa lahul-ḥamdu, wa huwa `alā kulli shai’in qadīr).’”