I don’t think I ever noticed this before, and it might be pushing the parable too far, but there is an interesting parallel to Christian belief about eternal Judgement in the parable of the Unforgiving Servant (Matthew 18:23-35).
The servant was originally threatened with punishment because of his debt. That debt was forgiven him. He then refused to forgive someone else’s debt to him.
When the servant was eventually punished, it was not because of his debt exactly, but because he was not affected by the grace shown him.