Silsilah Sahihah

It is narrated from Sayyida Umm Salamah (may Allah be pleased with her) that the Noble Prophet (peace and blessings be upon him) was present in my house. Some of the noble Companions were sitting with him, engaged in conversation. Meanwhile, a man came and asked: "What is the amount of zakat on this much (quantity) of dates?" The Messenger of Allah (peace and blessings be upon him) replied: "This much dates." He said: "So-and-so has wronged me and taken this much dates from me, that is, he has taken one sa‘ more." The Prophet (peace and blessings be upon him) said: "What will happen when rulers are imposed upon you who will wrong you much more than this?" The people began to ponder, and this hadith left them astonished, until a man spoke up: "O Messenger of Allah! If a man is far from you, settled with his camels, cattle, and crops, and he pays the zakat on his wealth, but he is wronged, what should he do, and he is also absent?" The Messenger of Allah (peace and blessings be upon him) said: "Whoever has paid the zakat on his wealth, while his soul is content, seeking Allah’s pleasure and the Hereafter, and he has not concealed any part of his wealth, and he establishes prayer and pays zakat, but he is wronged, and because of that he takes up his weapon and begins to fight, and is killed, then he is a martyr."