Why were Nadab and Abihu punished for issuing a halakhic ruling in their teacher’s presence if one may rule in order to prevent a prohibition?

This source-based Torah study examines the question: Why were Nadab and Abihu punished for issuing a halakhic ruling in their teacher’s presence if one may rule in order to prevent a prohibition? The canonical Hebrew discussion develops the issue through the weekly Torah portion and the sources cited there, preserving the distinctions, tensions, and practical implications of the original text. This localized discovery layer does not add any new halakhic, medical, legal, scientific, historical, theological, or empirical ruling or claim beyond the canonical Hebrew source.