There are a number of weights and capacities which have been specifically mentioned in the body of hadith; some are related to acts of worship and so make it necessary to act upon the exact amount. There are a number of papers written on this topic (Muhammad, 2001) (al-Kurdi, 2005); however our study will be more focused. The one of particular interest in this discussion is the Ṣāʿ which is used to calculate the ṣadaqa al-fitr, the fidya for not keeping fasts and also as kaffāra (expiation) of sins. (Hasan Hallāq, 2007)
There are three types of means to determine quantities recorded from the days of the Prophet may Allah send salutations and peace upon him; waẓn (pl. al-Awẓān) weight, qiyās (pl. al-Aqyisa) measure and kayl (pl. al-Akyāl) capacity. Our focus is going to be on the latter which is kayl (capacity) in determining the quantity of a ṣāʿ; we will however touch on a number of al-Akyāl and al-Awẓān when determining it as some are its components.
There are a number of traditions which mention as to what weight and capacity should be based on; I will quote one to make the point:
“Determining capacities is based on the capacities of the People of Madina and determining weights is based on the weights of the People of Makka.”
This is because the dirham and dinar were weighed which was based on the main occupation of the Muslims in Makka, in other words trade; and as foodstuff commodities had their capacities determined which was based on the main occupation of the Muslims in Madina, in other words farming. Therefore, niṣab for Zakah is calculated based on the Makkan measure and those issues associated with the ṣāʿ is calculated based on the Medinan measure.
I will attempt to separate the weights and the capacities but there will be some necessary comparative discussion due to the fact that certain weights also equate to capacities; this will be of interest as weights and volumes cannot be identical of various commodities due to their different densities.
It must also be said from the outset that there is disagreement amongst the fuqaha on many of the measures, therefore I will not discuss all the views on every issue. Having said that, on key measures the four schools will be mentioned. I am also not going to source the evidence for the positions of the schools as that is beyond the scope of this paper.Measuring the Capacity of the Ṣāʿ