What is the most suitable effect of fronting li-rabbihi in 100:6?

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

• Explicitly excluding every other relation through absolute restriction
• Making kanūd the grammatical subject
• Foregrounding ingratitude toward the Lord who gives blessings
• Eliminating the grammatical presence of the oath