ثبوت الحكم بها عند وجود النية، أو بدلالة الحال
An allusive expression produces its effect when intention or the circumstances indicate the intended meaning.
Intention chooses one of the expression's possible meanings. Dalālat al-ḥāl is the evidence supplied by the surrounding situation: the subject under discussion, the setting, and what the statement is responding to.
For example, language of separation uttered during a discussion of divorce may be interpreted in light of that context. The key issue is whether the context genuinely makes one legal meaning more probable than the alternatives.