Umm Salama bint Abu Umaya reported,
The Prophet of Allah ﷺ said, "Whoever pays the zakat on his wealth willingly and with a contented heart, seeking thereby the face of Allah and the abode of the Hereafter, concealing nothing of his wealth, and establishes the prayer, then pays the zakat, and is then wronged so that he takes up his weapon and fights and is killed, he is a martyr."
Azami 316
Hasanعن أم سلمة
أن نبي الله ﷺ قال: من أدى زكاة ماله، طيب النفس بها، يريد بها وجه الله والدار الآخرة لم يغيب شيئا من ماله، وأقام الصلاة، ثم أدى الزكاة فتعدى عليه الحق فأخذ سلاحه فقاتل فقتل فهو شهيد.
Imam Ahmad narrated it (26574), and Tabarani in al-Kabir (23/287), both through the route of Ubaydullah bin Amr, from Zayd bin Abu Unaysa, from Qasim bin Awf, from Ali bin Husayn, who said, "Umm Salama narrated to us," and he mentioned the hadith in full, which will come in its place. Imam Ahmad abridged it and did not mention the point of relevance, which is "seeking by it the face of Allah." Ibn Khuzayma graded it sahih (2336), as did Ibn Hibban in his Sahih (3193), and Hakim (1/404–405), all of them through the route of Ubaydullah bin Amr, who is al-Raqqi, with his chain, giving the hadith in full.Hakim said, "Sahih according to the standard of the two Shaykhs." This is a mistake on his part, for Qasim bin Awf, who is al-Shaybani al-Kufi, is not among the narrators of Bukhari. Rather, Muslim alone narrated from him. Moreover, there is disagreement about him. Abu Hatim said, "His hadith is disordered, though his standing is one of truthfulness." Ibn Adi said, "He is among those whose hadith is written down," meaning for corroboration, so his hadith is hasan with slight weakness in my view.And Ali bin Husayn is the son of Ali bin Abu Talib, Zayn al-Abidin.