How could Nadab and Abihu have been punished by Heaven if they had not yet reached the age of twenty?

This source-based Torah study examines the question: How could Nadab and Abihu have been punished by Heaven if they had not yet reached the age of twenty? 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.