In Fariduddin Attar's 'The Conference of the Birds' (Mantiq al-Tayr), the tale of the Sheikh who refuses to draw back his robe from a passing dirty dog serves as a profound lesson in spiritual humility. When questioned about his behavior by an onlooker, the Sheikh explains that while the dog's impurity is outward and visible, his own impurities are hidden within his heart. By comparing his inner state to the dog's outer state, the Sheikh teaches that true spiritual seekers must focus on recognizing and cleansing their own internal flaws rather than judging the superficial or external impurities of others. The story emphasizes the Sufi prioritization of inner purity over outward piety and self-righteousness.