Sahih al-Bukhari 3126
Book 57: One-fifth of Booty to the Cause of Allah (Khumus) · Narrated by Abu Musa Al-Ash`ari
Arabic
حَدَّثَنِي مُحَمَّدُ بْنُ بَشَّارٍ، حَدَّثَنَا غُنْدَرٌ، حَدَّثَنَا شُعْبَةُ، عَنْ عَمْرٍو، قَالَ سَمِعْتُ أَبَا وَائِلٍ، قَالَ حَدَّثَنَا أَبُو مُوسَى الأَشْعَرِيُّ ـ رضى الله عنه ـ قَالَ قَالَ أَعْرَابِيٌّ لِلنَّبِيِّ صلى الله عليه وسلم الرَّجُلُ يُقَاتِلُ لِلْمَغْنَمِ، وَالرَّجُلُ يُقَاتِلُ لِيُذْكَرَ، وَيُقَاتِلُ لِيُرَى مَكَانُهُ، مَنْ فِي سَبِيلِ اللَّهِ فَقَالَ " مَنْ قَاتَلَ لِتَكُونَ كَلِمَةُ اللَّهِ هِيَ الْعُلْيَا فَهْوَ فِي سَبِيلِ اللَّهِ ".
English translation
Narrated Abu Musa Al-Ash`ari:A bedouin asked the Prophet, "A man may fight for the sake of booty, and another may fight so that he may be mentioned by the people, and a third may fight to show his position (i.e. bravery); which of these is regarded as fighting in Allah's Cause?" The Prophet (ﷺ) said, "He who fights so that Allah's Word (i.e. Islam) should be superior, fights for Allah's Cause
Reference: Sahih al-Bukhari 3126, Book of One-fifth of Booty to the Cause of Allah (Khumus). English translation by Dr. Muhammad Muhsin Khan.