It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said to me: O Abu Huraira! Shall I not teach you a word which is a treasure of Paradise and has come from beneath the Throne? I said: Certainly, may my parents be sacrificed for you. The Prophet (peace and blessings be upon him) said: Say like this: La hawla wa la quwwata illa billah.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 8660
Hadith Gradingحکم دارالسلام:حدیث صحیح ، وھذا إسناد حسن