Is it permissible to enter into a Salam contract for an item defined by an existing physical sample?

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

Al-Mughni

Book of Sales

Book 12 · Issue 3 · Bab 6

Open in Qurani

Primary text

It is not permissible to enter into a Salam contract where one presents a cloth and states, "I have sold to you via Salam for the likes of this cloth." This is invalid due to the inherent uncertainty regarding the exact nature or quantity of the item being contracted for.