What is the legal basis for compensation for attorney's fees incurred due to the debtor's unjustified delay?

The claim for compensation is based on the harm suffered by the creditor due to the debtor's failure to pay the due entitlement, which compelled the creditor to incur attorney's fees. This is founded upon the Islamic legal maxim of "no harm and no reciprocal harm" (لا ضرر ولا ضرار), and on the opinions of jurists that permit obligating the defaulting party to compensate the right-holder for the expenses incurred due to the customary legal action.