Lender referring a third party to debtor for extra money

Iloaned someone ten thousand riyaals, but he is delaying repayment and has not yet paid back what he owes. I owe a third person ten thousand riyaals, and he came and asked for his money. I told him, ‘Go and ask So and so – i.e., the first person – for the ten thousand riyaals that I owe you, for the ten thousand that he owes me, and I will give you two thousand riyaals extra, to make up for the length of the delay. In other words, twelve thousand riyaals in return for ten thousand. What is the ruling on that? Please advise me, may Allaah reward you.