The nasal passage

The mechanic

The upper nasal cavity, which produces no letter of its own but is the exclusive outlet for the ghunna carried by ن and م. Pinching the nose stops it.

Where it occurs

The letters the ghunna belongs to

ن م

A place in the text

قُلۡ أَعُوذُ بِرَبِّ ٱلنَّاسِ

The marked spot was located in this ayah's own text at build time — An-Nas 114:1.