Why is wāw appropriate between the last two verses of az-Zalzalah?

Supplementary Practice 25 — Comparative Rhetoric of Sūrat az-Zalzalah and Sūrat al-ʿĀdiyāt

• Because the two clauses lack any semantic relation
• Because the second is only a word-for-word synonym of the first
• A shared structure and topic link two distinct conditional judgments
• Because wāw is identical in function to a causal lām