The Holy Prophet (s.a.w.a.) informed – …it was written on the base of Arsh – There is no God but Allah. Muhammad (s.a.w.a.), Ali (a.s.), Fatima (s.a.), Hasan (a.s.) and Husain (a.s.) are the best of creation.
Then Jibrail supplicated – O Lord, I ask you by their right on You that you make me their servant.
Allah replied – I have done so.