«وَلَمَّا أَحْضَرَ الْغُلَامُ مَا رَاحَ وَأَذْكَى بَيْنَنَا السِّرَاجَ تَأَمَّلْتُهُ»
When the servant brought what was at hand and brightened the lamp among us, I examined the visitor closely.
The servant lights the lamp and the narrator examines the visitor. The earlier presence had been mediated by sound and speech; illumination now makes close visual scrutiny possible. Light is therefore a practical condition for the next stage of knowing.
The sequence matters: arrival, conversation, lighting, inspection, recognition. If the identity were disclosed before the lamp, that careful build-up would vanish. A material action in the room becomes a turning point in the distribution of information to narrator and reader.