The Ruling on Accepting an Increase from the Debtor at the Time of Repayment

Question:
I am Fadi. He says: Honorable Shaykh, may Allah grant you success, I gave a man one thousand riyals. When the time for repayment came, he came and gave me my right plus an extra amount, but I did not accept the extra. He said, "This is a gift from me to you." What is the ruling?

Answer:
If the increase was not stipulated, but rather it is a voluntary gift from the debtor, this is a good way to settle the debt, and there is nothing wrong with it. However, if it was stipulated from the beginning, such as saying, "I will not give you the loan unless there is an increase," this is forbidden. But if he lent it to him as a favor for the sake of Allah, and then the debtor gave him more at the time of repayment, the Prophet (peace and blessings be upon him) said, "The best of you are those who are best in settling their debts." He (peace and blessings be upon him) borrowed a camel. When the owner of the camel came to collect it, they could not find anything but a camel that was better than the one he had lent. So he (peace and blessings be upon him) said, "Give it to me, for the best of you are those who are best in settling their debts." Is there no serious harm? Yes.