Thabit (may Allah have mercy on him), the freed slave of Umar bin Abd al-Rahman, said that when what happened took place between Abdullah bin Amr (may Allah be pleased with them both) and Anbasah bin Abi Sufyan (may Allah be pleased with him), they prepared for fighting. So Khalid bin al-As (may Allah be pleased with him) rode to Abdullah bin Amr (may Allah be pleased with them both) and admonished him. Abdullah bin Amr (may Allah be pleased with them both) said: Do you not know that the Messenger of Allah (peace and blessings be upon him) said: "Whoever is killed defending his property is a martyr."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب صلاة الخوف / 6059