What was the sin of Moses and Aaron at the waters of Meribah, and how can the severe punishment be understood?

This Torah study examines the question: What was the sin of Moses and Aaron at the waters of Meribah, and how can the severe punishment be understood? The canonical Hebrew discussion develops the issue through the weekly Torah portion and the sources cited there, preserving the distinctions, tensions and practical implications that belong to the source itself. This localized layer is designed for study and discovery; it does not add a new halakhic, medical, legal, historical or empirical ruling beyond the canonical Hebrew source.