حكمه: وجوب ما ثبت بها قطعاً، وتفيد عموم الحكم لعموم علته.
The source treats a ruling established through dalalah as binding and says that the ruling extends in keeping with the generality of its rationale.
In the example, the point is not merely the letters of the word “uff,” but the harm or disrespect understood from the language. A more severe case clearly sharing the same rationale is covered a fortiori.
The rationale must still be established; the doctrine does not authorise extension to unrelated cases simply because an analogy seems rhetorically attractive.