Buying a bag of crushed grain, then using a small amount from it, and if it does not suit him, taking another bag in its place with the seller’s consent!

Question:
He says: Honorable Shaykh, may Allah grant you success. I buy a bag of crushed grain, then I open it and use a small amount from it for a trial. If it does not suit me, I return this bag and take another bag, another bag of crushed grain of a different type. Is this permissible? Knowing that the shop owner has agreed to this?

Answer:
There is nothing wrong with that. This is not a sale. This is not a sale of crushed grain for crushed grain. This is a sale of crushed grain for dirhams. The first crushed grain did not suit you, so you returned it and took better crushed grain. There is no harm. Yes.