Context of speech requires attending to the setting and manner of a statement. The textbook’s historical discussion of assurances of safety in war contrasts two expressions.
«انزل»
Come down.
«انزل إن كنت رجلا»
Come down if you are a man.
The first, in the stipulated setting, can convey an assurance of protection, but the second is a challenge, not a promise of safety. An identical imperative can have a different legal purport when placed in a different context.
For an indication arising from the speaker’s situation, the book names yamin al-fawr, an oath whose immediate prompting occasion limits its scope.