Buying and Selling: Transacting by Measure for Commodities Bought and Sold by Weight
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 2102
Something that is bought and sold by weight can also be transacted by measure; for example, a person wishes to sell 10 kilograms of wheat and uses a measuring vessel that has the capacity to hold 1 kilogram of wheat and sells ten of these measures.
-Ayatullah Sistani, Practical Laws of Islam, Buying and Selling