Why do some people fast on the anniversary of the spies’ death?

This source-based Torah study examines the question: Why do some people fast on the anniversary of the spies’ death? 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.