Thus, for example, the zakah on forty million is one million, obtained by dividing it by forty. This is preferable to the common expression that what is due is two and a half percent, because it gives the impression that there is an exempt interval: a person may suppose that every one hundred incurs two and a half, while the amount between one hundred and two hundred is an exempt interval on which nothing is due. This is a serious matter.
His statement, “Once it reaches twenty mithqals,” explains the minimum taxable amount for gold, based on the hadith of Ali ibn Abi Talib—may Allah be pleased with him—that the Prophet—peace and blessings be upon him—said: “If you possess twenty dinars and a full year passes over them, then half a dinar is due on them.” (1) Other hadiths have also been narrated from the Prophet—peace and blessings be upon him—with this meaning, as well as Companion reports not traced back to the Prophet. Taken together, they reach the level of acceptable—or authentic—by virtue of corroboration. As for Ibn Abd al-Barr’s statement—may Allah have mercy on him—that nothing concerning this has been established from the Prophet—peace and blessings be upon him—it may be answered that it has indeed been established with sufficient evidence for it to serve as proof.
The Islamic dinar weighs one mithqal, and a mithqal is four and a quarter grams. Every ten Islamic dirhams equal seven mithqals; accordingly, two hundred dirhams equal one hundred and forty mithqals.
I have determined the minimum taxable amount for gold to be eighty-five grams of pure gold. (2) If it contains a slight admixture, it is subsidiary and does no harm, because