In threats, a speaker may outwardly say something he plainly does not wish the listener to do. The aim is to make the listener feel the danger of taking that course.
Surface wording of “lā tuṭiʿ amrī”: Do not obey my order.
Intended force: Disobedience will bring punishment or harm.
Contextual cues: Reproach, authority, mention of defiance, and an implied harsh consequence.
Rhetorical analysis distinguishes “What does the form say?” from “What does the speaker intend here?” Tahdīd depends on that difference.