Is specifying the weight of the textile valid in a contract of forward sale?

Chapter on Guaranteed Salaf (Advance Payment) for a Specified Term

Al-Mughni

Book of Sales

Book 12 · Issue 2 · Bab 6

Open in Qurani

Primary text

Specifying the weight of the textile is not valid. If the weight is mentioned, the contract is void because it becomes impossible to reconcile the specified attributes with a known weight, leading to potential deception (taghrir) due to the impossibility of exact agreement on the weight.