Ruling on giving a buyer a number in a draw for a specific amount

Question:
Peace be upon you and Allah's mercy and blessings. In some commercial establishments, there are milk products. If a buyer purchases an amount equivalent to approximately one hundred riyals, he receives a number. This number may win a car or a valuable watch. Is there any harm in this? Please inform us. May Allah reward you with good.

Answer:
We have written about this, and the Committee has stated that it is gambling, and it is not permissible. This is because he is buying based on the number: who knows? Will he win a prize or not? Perhaps a great deal of money will be lost by people because of this prize.
However, if it is specified, for example, saying: "Whoever buys from us four times for such an amount, or five times for such an amount, we will give him such an item, or we will give him an additional known amount," there is no harm if it is known. For instance, if he buys from us for one hundred riyals, we give him one or two liters, or if he buys from us for ten thousand riyals of such and such items, from specific types, we reduce the price for him in the last hours by such and such, and so on. The matter in this case is clear, and there is no excessive uncertainty.