Can an etrog that was kept under a bed still be used to fulfill the mitzvah?

This Torah study examines the question: Can an etrog that was kept under a bed still be used to fulfill the mitzvah? 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.