What is the rhetorical contribution of opening with al-qāriʿah by itself?

Supplementary Practice 26 — Comparative Rhetoric of Sūrat al-Qāriʿah and Sūrat al-Tīn

• Completing the nouns governed by an oath
• Awe at the event and undivided focus upon it
• Identifying a specifically named person
• Issuing an explicit negative order