Sunan an-Nasa'i, Volume 5, Book 37, Hadith 4090 (DarusSalam) ⓘ
It was narrated that 'Abdullah bin 'Amr said: "I heard the Messenger of Allah [SAW] say: 'Whoever fights to protect his wealth and is killed, he is a martyr.'"
أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ بَزِيعٍ، قَالَ حَدَّثَنَا بِشْرُ بْنُ الْمُفَضَّلِ، عَنْ أَبِي يُونُسَ الْقُشَيْرِيِّ، عَنْ عَمْرِو بْنِ دِينَارٍ، عَنْ عَبْدِ اللَّهِ بْنِ صَفْوَانَ، عَنْ عَبْدِ اللَّهِ بْنِ عَمْرٍو، قَالَ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " مَنْ قَاتَلَ دُونَ مَالِهِ فَقُتِلَ فَهُوَ شَهِيدٌ " .
also referenced under: Hadith 4085 (Reference) & Book 37, Hadith 120 (In-Book)