The Prophet ﷺ said: If the property of anyone is designed to be taken away without any right and he fights and is killed, he is a martyr. (Using translation from Abū Dāʾūd 4771)
أَنَّ النَّبِيَّ ﷺ قَالَ مَنْ أُرِيدَ مَالُهُ بِغَيْرِ حَقٍّ فَقُتِلَ فَهُوَ شَهِيدٌ