What is the ruling when there is a dispute regarding the master's exoneration of the Mukatab from the debt of manumission or part of it?

Primary text

If a dispute arises concerning whether the master has absolved the Mukatab from the financial obligation of manumission, or any portion thereof, the statement of the master is upheld, contingent upon his taking an oath. This ruling is based on the principle that the burden of proof rests against the claimant in such matters, favoring the master's position when he affirms the existence of the debt or denies the exoneration.