Majma al-Zawaid — Hadith 4443

Sayyidah Umm Salamah (may Allah be pleased with her) narrates: The Prophet (peace and blessings be upon him) was in my house when a man came and said: "O Messenger of Allah! How much is the zakah on such-and-such a thing?" The Prophet (peace and blessings be upon him) said: "It is such-and-such." He said: "Then so-and-so has wronged us." The narrator says: When they investigated, they found that he had taken one sa' too much. The Prophet (peace and blessings be upon him) said: "What will your state be when a collector comes to you who will wrong you more severely than this wrong?"
Ahmad recorded it in this way. Al-Tabarani recorded these additional words in this narration: "He will wrong you more than this wrong. Then those people became greatly distressed, and this statement troubled them, until one of them said: 'O Messenger of Allah! What will happen when a man is away from you among his camels, his livestock and his fields, and he pays the zakah of his wealth and is then wronged; what should he do at that time, while he is not present with you?' The Prophet (peace and blessings be upon him) said: 'Whoever pays the zakah of his wealth with a willing heart, intending by it the pleasure of Allah Almighty and the attainment of the Hereafter, and does not conceal anything of his wealth, and establishes the prayer and pays the zakah, and is then wronged in a matter of right, then if he takes up his weapon and fights and is killed, he will be counted a martyr.'"
Al-Tabarani recorded it in al-Mu'jam al-Kabir and al-Mu'jam al-Awsat, and the narrators of all of them are the narrators of the Sahih.