Adbullaah Ibn Qays (radhi-yAllaahu 'anhu) related that The Prophet (sal-Allaahu 'alayhe wa sallam) said to him: O 'Adbullaah Ibn Qays, shall I not inform you of a treasure from the treasures of paradise? He (sal-Allaahu 'alayhe wa sallam) then said: Say:

لاَ حَوْلَ وَلاَ قُوَّةَ إِلاَّ بِاللَّهِ

There is no might nor power except with Allaah.

Laa hawla wa laa quwwata 'illaa billaah.

Al-Bukhari , Muslim 4/2076