Few scriptures anywhere are used as heavily. In Japanese Zen and Shingon temples the Hannya Shingyo is chanted at services and copied by hand as shakyo, a devotional discipline practised by laypeople with no particular doctrinal training. Korean Son, Vietnamese Thien and Chinese Chan monasteries recite it daily. In Tibetan monasteries it is chanted before teachings, often with an added recitation to dispel obstacles, and the Dalai Lama has taught on it repeatedly. It is written on fans, printed on cloth, worn as an amulet.
Its commentarial tradition is correspondingly deep, and its brevity is why: a text this compressed demands explanation, and every school has supplied one. Indian commentaries survive in Tibetan translation; Kuiji and Woncheuk wrote on it in seventh-century China from a Yogacara standpoint; Fazang read it through Huayan; Tibetan commentators approach it through Madhyamaka, with the negations understood as a scriptural statement of Nagarjuna's analysis. The same page supports readings that disagree substantially with each other about what emptiness means.
Its function in practice is not primarily argumentative. The sutra is used as protection, as a focus for concentration, as the frame within which a service begins, and simultaneously as the most concise statement Mahayana has of its central philosophical claim. That double life, liturgical object and philosophical text at once, is unusual, and it explains why a work whose content is systematic negation is also the piece of Buddhist scripture most likely to be found on a wall.