Measure (kayl), fiqh rulings

Kayl, in lexicon, is the act of measuring, the measure by which quantity is known, such as a qafiz, a mudd or a sa', and the vessel used for measuring; a kayli is what is measured by volume. Measuring tells a thing's volume and weighing its weight ^{1 2}.

The law urges full measure and warns those who cheat. The surah of the Cheats and a verse of the surah of the Poets (verse 181) are cited, without quoting the text here ². Al-Qurtubi reports from Ibn Abbas that the people of Medina used to take full measure when buying and cheat when selling, and stopped when these verses came down; some scholars count cheating in measure among the major sins ².

The jurists agree that in the sale of a measured thing the cost of measuring is on the seller, and for a weighed thing the cost of weighing is on the seller, since he must deliver it and delivery is not complete without this. The cost of measuring the price, and bringing it to the place of contract when absent, is on the buyer ². Detail is in the entry on sale ².

The text forbids riba in gold, silver, wheat, barley, dates and salt, weight for weight and measure for measure ². Jurists differ on the cause that extends the rule: the Hanafis take genus and measure; in the most common Hanbali view the cause is weight with genus for the two metals and measure with genus for the others; in the old Shafi'i view it is food in the others, and in the new view food and, for the two metals, the general use as money; the Malikis take the currency value for money and staple food and storage for food ^{2 3}.

Jurists agree that what is ordered in advance must be of known quantity, on the hadith: whoever pays in advance for a thing shall pay by a known measure and weight for a known term ⁴. The Hanafis and Shafi'is do not require measuring by measure itself, only knowing the quantity by either measure or weight; the Shafi'is exclude some kinds and the two metals, which are ordered by weight only ⁴. The Malikis require a quantity fixed by measure, weight or count, as custom runs. The Hanbalis differ on ordering a measured thing by weight; Ahmad, as reported by al-Athram, allowed it only by measure ^{4 5}.

Jurists in general agree that measured goods may not be sold before they are received. The Hanafis forbid the buyer of a measured thing to sell or eat it before measuring it again, on the hadith forbidding sale of food until two measures, the seller's and the buyer's, are taken. The Shafi'is treat measuring as part of receipt, on the hadith: whoever buys food must not sell it until he has measured it. The Hanbalis hold a sale valid if the seller tells the buyer the measure, but Ahmad in one report requires measuring again ^{5 6}.