«وَالتَّمْيِيزُ عِنْدَنَا بَيْنَ الْفِضَّةِ وَالْقِضَّةِ مُتَيَسِّرٌ»
We can readily distinguish silver from little stones.
Fiḍḍah is silver; qiḍḍah refers here to small stones or gravel. The near-identical forms contrast objects of unequal value, dramatizing the assembly's confidence in its powers of criticism.
The closeness of the sounds produces a form of partial paronomasia. The members imply that they can separate fine prose from poor imitation. Whether they actually can do so remains the issue under examination.