ENOfficial
It was narrated from Sulaiman bin Buraidah that his father said: "The Messenger of Allah (ﷺ) said: 'Whoever is killed defending his wealth, he is a martyr.'"
Source: sunnah.com
Other translations
Arabic
أَخْبَرَنَا أَحْمَدُ بْنُ نَصْرٍ، قَالَ حَدَّثَنَا الْمُؤَمَّلُ، عَنْ سُفْيَانَ، عَنْ عَلْقَمَةَ بْنِ مَرْثَدٍ، عَنْ سُلَيْمَانَ بْنِ بُرَيْدَةَ، عَنْ أَبِيهِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ قُتِلَ دُونَ مَالِهِ فَهُوَ شَهِيدٌ " .
sunnah.com