How is Zakat calculated on amounts exceeding the Nisab threshold for silver and gold?
Chapter on Zakat on Gold and Silver
Al-Mughni
Book of Zakat
Primary text
For silver that exceeds two hundred dirhams, the calculation follows the established rate, as proven by the narration from Ali, "Bring one-quarter of a tenth from every forty dirhams, one dirham, and there is nothing upon you until two hundred is complete. When there are two hundred dirhams, there are five dirhams, and whatever is added is calculated accordingly." This view, attributed to Ali and Ibn Umar without known contradiction from other Companions, amounts to consensus. Furthermore, as it is traded wealth, it should not have an exemption after the Nisab, unlike grain.
Supporting text
The opposing argument based on the first narration (regarding forty dirhams) is considered an argument from the context (Daleel al-Khitaab), which is superseded by explicit statement (Mantuq). The narration used to support the view of exemption after the Nisab is reported by Al-Jarraah bin Manhal, who is considered abandoned in hadith narration; Malik reportedly called him a deceiver. Moreover, the chain of narration for that hadith involves Ubadah bin Nasi, who did not meet Mu'adh, making it a Mursal narration. Additionally, livestock are difficult to precisely subdivide, unlike monetary values.