Sahih Bukhari
Fighting for the Cause of Allah (Jihaad)
Volume: 004 / Book Number: 052 / Hadith Number: 145
Narrated Mus'ab bin Sad:
Once Sad (bin Abi Waqqas) thought that he was superior to those who were below him in rank. On that the Prophet said, "You gain no victory or livelihood except through (the blessings and invocations of) the poor amongst you."