«وَكَانَ بِالْمَجْلِسِ كَهْلٌ جَالِسٌ فِي الْحَاشِيَةِ»
An older man sat at the edge of the gathering.
During a discussion of eloquence, an older man sits at the edge of the gathering. The detail plants a potentially important figure in the scene without immediately advertising his abilities. His marginal position contrasts with the confident speakers at the centre.
The reader should track who has spoken, who has listened and whose competence has not yet been tested. A previously quiet character may become crucial later, but silence itself proves neither expertise nor ignorance. The narrative effect lies in keeping a possible reversal available.