What established grammatical analysis is offered for the accusative al-muqīmīna al-ṣalāh?

Legal Inference, Interpretive Clarification, and Supporting Disciplines of Tafsir

• Treat it as necessarily a nominative topic
• Insist it is a cognate accusative of an omitted verb
• Treat it as genitive after a preposition
• Accusative of commendation or specification