Sahih Bukhari Volume 009, Book 093, Hadith Number 550.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 93. Oneness, Uniqueness of Allah (Tawheed)
Narrated By Abu Musa : A man came to the Prophet and said, "A man fights for pride and haughtiness another fights for bravery, and another fights for showing off; which of these (cases) is in Allah's Cause?" The Prophet said, "The one who fights that Allah's Word (Islam) should be superior, fights in Allah's Cause." (See Hadith No. 65, Vol. 4)