What does the repeated wa-wajadaka ... fa- pattern achieve?

Supplementary Practice 18: Rhetorical Analysis of Sūrat al-Ḍuḥā and Sūrat al-Sharḥ

• It forces all three verses to convey identical meanings
• It turns every wāw into an oath particle
• It parallels an earlier condition with its corresponding relief
• It makes fā a marker of negation