«إِلَّا بِتَخَطِّي رِقَابِ الْجَمْعِ»
Except by stepping over the people in the crowd.
Al-Ḥārith wants to approach the elder immediately, but the gathering is crowded. He avoids forcing his way across people and disturbing them. This creates a moral contrast between satisfying personal curiosity and respecting those around him.