The companion of the Prophet (peace be upon him), Abu Musa Al-Ashari (RA) said,

"We were in the company of Allah's Messenger during a battle. Whenever we climbed a high place, went up a hill or went down a valley, we used to say, `Allah is the Most Great,' raising our voices.

The Prophet came by us and said:

O people! Be merciful to yourselves (i.e., don't raise your voices), for you are not calling a deaf or an absent one, but One Who is All-Hearer, All-Seer. The One Whom you call is closer to one of you than the neck of his animal.

O Abdullah bin Qais (Abu Musa's name) should I teach you a statement that is a treasure of Paradise:`La hawla wa la quwwata illa billah (there is no power or strength except from Allah).'

[Source: Tafsir Ibn Kaseer]

Recitation from Al-Qur'an: Surah Al Baqarah Ch.2 V.186
Reciter: Abdul-Basit ‘Abdel-Samad