반야심경
In the Mahayana canon, the "Heart Sutra" is ascribed entirely to Guanyin. This is unique, since most Mahayana Sutras are usually ascribed to Gautama Buddha and the teachings, deeds or vows of the bodhisattvas are described by Shakyamuni Buddha. In the "Heart Sutra", Guanyin describes to the arhat Sariputta the nature of reality and the essence of the Buddhist teachings. The famous Buddhist saying "Form is emptiness, emptiness is form" () comes from this sutra.