Validity of excepting currency from specie or specie from currency in an acknowledgment?
General Chapter
Al-Mughni
Book of Acknowledgment of Rights
Primary text
There are differing opinions among our jurists regarding the validity of excepting a specific coin/specie from currency (dirhams/dinars) or vice versa. Abu Bakr 'Abd al-'Aziz deems it invalid, similar to the view of Muhammad ibn al-Hasan. Ibn Abi Musa has two narrations on the matter. Al-Kharqi favors its validity because the value of one can be known from the other, allowing for them to be used interchangeably in certain local customs, thus allowing the statement to be interpreted correctly as an explanation.
Supporting text
Abu al-Khattab asserts there is no distinction between specie and currency versus other categories, meaning if one is validly excepted from the other, then exceptions of garments and others should also be valid. A reconciliation suggests that validity applies when one item defines the measure of the other, while invalidity applies when that linkage is absent.