Ephesians 6:5-9 to masters: threats and divine judgment, not divine institution

Ephesians 6:5-9: slaves told to obey with sincerity, as to Christ, knowing they'll receive reward regardless of status. Masters told to stop threatening, knowing 'he who is their master and yours is in heaven and there's no partiality with him.' This threatens masters with divine judgment -- very different from the marriage passage's creation/redemption grounding.