Is the testimony of a creditor for his debtor regarding defamation before the injury heals valid?

Primary text

The testimony of a creditor for his debtor regarding defamation before the injury heals is permissible. This is because the blood money (*diyah*) is not initially due to the creditor, but to the killed person or their heirs, from whom the creditor may later recover, making it analogous to testifying for a debt owed to the debtor.