Selling a car with a discount on an old debt

The presenter:
Sa'id, please turn the television down a bit, the one you have, because there is static.

The questioner:
Well, long may you live, I have a debt with a man. He asked me for a car and said, "Deduct the old amount." Is that permissible or not?

The Shaykh:
Yes, he asked you.

The questioner:
He asked me for a car, I give him a car. And I deduct the dynamic debt.

The Shaykh:
You always have a claim on him.

The questioner:
Yes, long may you live.

The Shaykh:
He wants you to sell him the car, what does the debt have to do with it?

The questioner:
I deduct the old debt.

The Shaykh:
How do you deduct it? The old debt remains as it is.

The questioner:
He says to the Shaykh, "Take the old debt and this car starts from scratch. I don't know if it is permissible or not."

The Shaykh:
You sell him the car for a separate price, and the debt remains as it is. If you wish to forgive it, or part of it, out of generosity, there is no harm in that. However, making this a condition is not permissible.

The presenter:
All right, thank you.