What is the ruling regarding specification of embroidery (washi) in a forward sale contract for textiles?

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

Al-Mughni

Book of Sales

Book 12 · Issue 6 · Bab 6

Open in Qurani

Primary text

If the embroidery (washi) is an integral part of the weaving process when the fabric is manufactured, the contract is valid. If the embroidery is an addition made after the main weaving, the contract is invalid because such additions cannot be precisely specified or controlled.