What constitutes a valid settlement concerning unknown debts or long-standing past transactions?

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A valid settlement includes a wife settling her dower when she has no proof, knowledge, or the heirs have no knowledge of its amount. Likewise, if a long history of transactions and accounting exists between two men where neither knows precisely what they owe the other, settlement between them is permissible. It is also valid for a person liable for a debt of unknown size to settle it, regardless of whether the creditor knows the amount or has proof, or if the creditor also lacks knowledge. This is expressed by the debtor saying, 'If I owe you a right, I release you from it,' and the creditor saying, 'If I took more than my due from you, I release you from it.'