حكمه: وجوب ما ثبت بها قطعاً.
The textbook states that what is established through this mode is binding with decisive force.
The word qatʿan expresses the strength assigned to this mode of indication. It should not be taken as a licence to ignore the text’s full context, qualifying evidence or relevant legal conditions.
Ibarat is the primary, purposive signification. The book later gives it priority when it truly conflicts with a meaning drawn through isharah.