From Sahih Muslim (Hadith 361):
It is narrated on the authority of Thabit, that when 'Abdullah b. 'Amr and 'Anbasa b. Abi Sufyan were about to fight against each other, Khalid b. 'As rode to 'Abdullah b. 'Amr and persuaded him (not to do so). Upon this Abdullah b. 'Amr said:Are you not aware that the Messenger of Allah (ﷺ) had observed:" He who died in protecting his property is a martyr
Reference: Muslim 361