Hadithcore
Mishkat al-Masabih, 3512

‘Abdallah b. 'Amr told of hearing God’s Messenger say, “He who is killed protecting his property is a martyr.” (Bukhari and Muslim.)

وَعَنْ عَبْدِ اللَّهِ بْنِ عَمْرٍو قَالَ: سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ: «مَنْ قُتِلَ دُونَ مَالِهِ فَهُوَ شهيدٌ»

References1 variant
In-Book Reference
Book 16, Hadith 59