Hadith
أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ الأَعْلَى، قَالَ حَدَّثَنَا خَالِدٌ، قَالَ حَدَّثَنَا حَاتِمٌ، عَنْ عَمْرِو بْنِ دِينَارٍ، عَنْ عَبْدِ اللَّهِ بْنِ عَمْرٍو، قَالَ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " مَنْ قَاتَلَ دُونَ مَالِهِ فَقُتِلَ فَهُوَ شَهِيدٌ " .
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
Sahih · Abu Ghuddah
Sunan an-Nasa'i 4084 ·Book 37, Hadith 119·Also available on sunnah.com·