The passage first contrasts fils / dhikr, qaṣr / birr, and thawb / thawāb. It then uses the sound relations of ṣilāt / ṣalāh, ṣaduqāt / ṣadaqāt, and ṣiḥāf / ṣaḥāʾif.
Near the end, parallel verbs such as tantahiku, tataḥāmā, taghshā, and takhshā sharpen the charge of hypocrisy. Balanced clauses and resonant endings exemplify sajʿ and rhetorical parallelism.
The sonic artistry serves meaning; rhyme alone is not the argument.