«فَقَلَّدُوهُ فِي هَذَا الْأَمْرِ الزَّعَامَةَ»
So they entrusted him with leadership in this matter.
Qalladū is a Form II past-tense plural verb, meaning here that they assigned someone responsibility or authority. Zaʿāmah means leadership. The narrator adds a historical comparison to intensify the formality of the delegation.
The exchange now has a clear structure: the elder asserts, the assembly doubts, and its representative assumes control of a proposed examination. His personal story will explain why he has chosen this test.