May one drink water left in a bottle after some of it was used for mayim acharonim?

This source-based Torah study examines the question: May one drink water left in a bottle after some of it was used for mayim acharonim? 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.