When a text prohibits a minor form of harm to parents, the prohibition of more severe harm can be understood through dalālat al-naṣṣ: the relevant meaning of harm is evident from the expression itself. No freshly invented external cause is needed simply to recognize greater harm.
By contrast, extending an established ruling to a new category because of a shared operative attribute calls for qiyās. Both should not be collapsed into “going beyond the original case.”
Key diagnostic: Does the further ruling follow from the readily understood language, or must an independently established operative cause be shown to exist in the new case?