Superiority of La haula wa la quwwata ilia Billah (There is no power and might except by Allah)
79) Narrated Abu Huraira that Allah's Messenger said: Should I not teach you or (probably) said: Shall I not show you a word from under the Divine Throne of Allah out of the treasure of Paradise? You should say (There is no power and no strength except by Allah).At this Allah will say: My slave has become a Muslim and has surrendered himself to My Will.
(This Haditli is good and reported in Mustadrak of AI-Hakim).
This phrase (No power or might except Allah's) is one of the highly rewarded as (There is no God, but Allah) and" (Allah is All-Great).