The Heart Sutra is chanted daily in Zen and Mahayana monasteries around the world. Its central line — form is emptiness, emptiness is form — states in six words the core Mahayana insight: appearance and emptiness are not two different things but two faces of the same thing.
The sutra is framed as a teaching from Avalokiteshvara to Shariputra. Its concluding mantra — gate gate paragate parasamgate bodhi svaha — “gone, gone, gone beyond, gone utterly beyond, awakening!” — resists translation and is usually chanted in Sanskrit.