Riyad as-Salihin

Sa'id bin Zaid bin 'Amr bin Nufail (May Allah be pleased with him) reported, one of the ten Companions who were given the glad tidings of entering Jannah reported: I heard the Messenger of Allah (ﷺ) saying: "He who dies while defending his property is a martyr; he who dies in defence of his own life is a martyr; and he who dies on defense of his faith is a martyr, he who dies in defence of his family is a martyr."

[Abu Dawud and At- Tirmidhi].