What is the syntactic role of taʿarruḍa?

Imruʾ al-Qays: A Guarded Tent, the Pleiades, Objection, and Dunes (Verses 23–29)

• A masculine sound plural subject
• A noun governed directly by a preposition
• A cognate accusative verbal noun related to taʿarraḍat
• A jussive conditional particle