Volume 4, Book 52, Number 65 :
Narrated by Abu Musa (radiallaahu `anhu)
A man came to the Prophet (sallallaahu `alayhi wasallam) and asked, “A man fights for war booty; another fights for fame and a third fights for showing off; which of them fights in Allah’s Cause?” The Prophet (sallallaahu `alayhi wasallam) said, “He who fights so that Allah’s Word (i.e. Islam) should be superior, fights in Allah’s Cause.”
The only acceptable intention is that of promoting Allah’s Deen. Wealth and fame are just “side benefits” but one must not seek them out of Jihad.
This is true for other types of Jihad as well. When one struggles in Allah’s Cause in the field of Dawah, education or welfare etc., wealth and fame do follow. While one might not be looking for these things in his efforts, they certainly put one’s sincerity in danger. Shaytan is always at work as we all know. One can never be too careful of the whispers. May Allah protect us all.
Another version of this hadith:
It is recorded in the Two Sahihs that Abu Musa Al-Ash`ari said, “The Messenger of Allah was asked about a man who fights because of courage, or out of rage for his honor, or to show off. Whom among them is in the cause of Allah’ The Prophet said,
«مَنْ قَاتَلَ لِتَكُونَ كَلِمَةُ اللهِ هِيَ الْعُلْيَا فَهُوَ فِي سَبِيلِ الله»
(He who fights so that Allah’s Word is superior, then he fights in Allah’s cause.)”
Ibn `Abbas commented,
`The Word of Allah’ is La ilaha illallah. [Tafsir Ibn Kathir 9:40]