The rule: If he acknowledges a debt to him, it is not permissible to settle it for more than that amount of the same kind
Machine translationRead the Arabic original
The questioner : Yes, Sharahi. If he acknowledges a debt to him, it is not permissible to settle it for more than that amount of the same kind. Is this absolute, or is there an exception to it?
The Shaykh : Ma'ish?
The questioner : The answer is that this is absolute; it is forbidden.
The Shaykh : It is absolute, because he is taking it without right. If he acknowledges a hundred sa' (a dry measure of about 3 kg) to him, how can he say, "I settle it for one hundred and twenty"? This does not need to be discussed; we say it is a hundred sa'. If you wish to give him the twenty as a gift, there is no harm in that.
The questioner : Shaykh, for example, is the increase in exchange for him leaving him alone and not complaining?
The Shaykh : It would be a reward without a settlement; he pays him his right and gives him a reward. Yes.
The Shaykh : Ma'ish?
The questioner : The answer is that this is absolute; it is forbidden.
The Shaykh : It is absolute, because he is taking it without right. If he acknowledges a hundred sa' (a dry measure of about 3 kg) to him, how can he say, "I settle it for one hundred and twenty"? This does not need to be discussed; we say it is a hundred sa'. If you wish to give him the twenty as a gift, there is no harm in that.
The questioner : Shaykh, for example, is the increase in exchange for him leaving him alone and not complaining?
The Shaykh : It would be a reward without a settlement; he pays him his right and gives him a reward. Yes.
Source
قناة «فضيلة الشيخ محمد بن صالح العثيمين»، [4662] ضابط إذا اعترف له بشيء، لم يجز أن يصالح بأكثر منه من جنسه - تعليقات على الكافي لابن عثيمين — youtube.com
The Arabic text is a machine transcription of the audio recording.