Sahih
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 " .
It was narrated from Sulaiman bin Buraidah that his father said:"The Messenger of Allah [SAW] said: 'Whoever is killed defending his wealth, he is a martyr