Adhesion (of tongue to palate)

The mechanic

Beyond merely lifting, the tongue's surface presses flat up against the palate so the sound is trapped between them. Four letters: ص ض ط ظ.

Where it occurs

The four itbaq letters

ص ض ط ظ

A place in the text

وَلِلَّهِۤ يَسۡجُدُۤ مَن فِي ٱلسَّمَٰوَٰتِ وَٱلۡأَرۡضِ طَوۡعٗا وَكَرۡهٗا وَظِلَٰلُهُم بِٱلۡغُدُوِّ وَٱلۡأٓصَالِ۩

The marked spot was located in this ayah's own text at build time — Ar-Ra'd 13:15.