When does charity fail to endure forever, and how can one avoid losing its protective merit?

This source-based Torah study examines: When does charity fail to endure forever, and how can one avoid losing its protective merit? It follows the canonical Hebrew discussion through the parasha and classical Jewish sources. This localized discovery layer is a concise summary rather than a full translation of the article; practical, halakhic, medical, legal, historical, mystical or empirical claims remain source-framed and subject to the canonical review status.