ويجوز أن يحط من الثمن
Translation: The seller may remit part of the purchase price.
If an item was sold for Rs 50,000 and the seller later deducts Rs 4,000, the remaining consideration is Rs 46,000. This is a reduction of the price. Under the relevant conditions it has effects upon the amount due under the original sale.
It should not be confused with an unrelated personal gift. After a valid reduction, the remaining debt and related delivery or withholding rights are assessed against the adjusted sum.