The Mantra of Purifying the Heart is recited at the beginning of Taoist rituals to cleanse the practitioner's mind of distracting thoughts, negative emotions, and spiritual turbidity. It invokes the protection of the Three Hun (ethereal soul) and Seven Po (corporeal soul), ensuring the practitioner's spiritual integrity remains whole. By calming the heart-mind (心神), it establishes a foundation of inner stillness necessary for deeper meditation, communication with deities, and the proper performance of sacred rites. This mantra is considered essential before any form of Taoist cultivation or ceremonial practice.