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.'"

أَخْبَرَنَا أَحْمَدُ بْنُ نَصْرٍ، قَالَ حَدَّثَنَا الْمُؤَمَّلُ، عَنْ سُفْيَانَ، عَنْ عَلْقَمَةَ بْنِ مَرْثَدٍ، عَنْ سُلَيْمَانَ بْنِ بُرَيْدَةَ، عَنْ أَبِيهِ، قَالَ قَالَ رَسُولُ اللَّهِ ﷺ " مَنْ قُتِلَ دُونَ مَالِهِ فَهُوَ شَهِيدٌ " .