Shaykh Sulaymaan Ar-Ruhaylee was asked:
Question Fourteen: the questioner says: I bought an item from one of the stores and I obtained a voucher for half [of the cost] of the item I bought. So what is the ruling on benefiting from these vouchers?
“If a person obtains [the voucher] for the item, then what is apparent to me is that there is no harm, if everyone can obtain it. For example: If you buy a thawb, you get another thawb [free] or for half the cost or the likes of that and this is for the item, then there is no harm. As for if it is wealth [that is given], then it is not allowed”.
[al-Qawaa’id ul-Fiqhiyyah al-Mut’alliqah bil-Buyoo’ (pg. 288)]
Faisal Ibn Abdul Qaadir Ibn Hassan