Sunan an-Nasa'i, Volume 5, Book 37, Hadith 4095 (DarusSalam) ⓘ
It was narrated from Sa'eed bin Zaid that: The Prophet [SAW] said: "Whoever is killed defending his wealth, he is a martyr." This is an abridgement of it.
أَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، وَقُتَيْبَةُ، - وَاللَّفْظُ لإِسْحَاقَ - قَالاَ أَنْبَأَنَا سُفْيَانُ، عَنِ الزُّهْرِيِّ، عَنْ طَلْحَةَ بْنِ عَبْدِ اللَّهِ بْنِ عَوْفٍ، عَنْ سَعِيدِ بْنِ زَيْدٍ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " مَنْ قُتِلَ دُونَ مَالِهِ فَهُوَ شَهِيدٌ " .
also referenced under: Hadith 4090 (Reference) & Book 37, Hadith 125 (In-Book)