In Book One, Section 16 of the Masnavi, Rumi introduces the metaphor of a granary infested by a mouse to illustrate the mechanics of spiritual attrition. The granary represents the seeker's soul or their accumulation of good deeds and spiritual practices (symbolized by wheat), while the hidden mouse symbolizes the lower self (nafs) or deceptive external influences (such as the deceitful vizier). Just as a mouse secretly consumes stored grain, the unchecked ego steadily drains a person's spiritual merits. Rumi teaches that before attempting to accumulate more good deeds, one must first identify and eliminate this inner thief; otherwise, spiritual efforts are continuously undermined and wasted.