The Heart Sutra is frequently referred to in Zen Buddhism; in some monasteries it is recited at every meal, and the monks are expected to know it by heart. There are some minor variations, but the Sutra consists of a little over two hundred Chinese characters, each of which is a monosyllable. Here is a translation which follows the commentary of a well-known Zen master of this century, Obora Ryoun.
‘When the Bodhisattva Kannon was practising the profound Prajna Paramita wisdom he saw all the five aggregates to be Emptiness, and passed beyond suffering.
O disciple Shariputra, form is not different from Emptiness, Emptiness is not different from form; form is Emptiness and Emptiness is form; and so also with sensation, thinking, impulse and consciousness. All these things, Shariputra, have the character of Emptiness, neither born nor dying, neither defiled nor pure, neither increased nor lessened.
So in Emptiness there is neither form nor sensation, thinking, impulse nor consciousness; no eye, ear, nose, tongue, body nor mind; no form, sound, smell, taste, touch nor object of mind; no element of eye, nor any of the other elements, including that of mind-consciousness; no ignorance and no extinction of ignorance, nor any of the rest, including age-and-death and extinction of age-and-death; no suffering, no origination, no stopping, no path; no wisdom and no attainment.
The Bodhisattva, since he is not gaining anything, by the Prajna Paramita has his heart free from the net of hindrances, and with no hindrances in the heart there is no fear. Far from all perverted dream thoughts, he has reached ultimate Nirvana. By the Prajna Paramita all the Buddhas of the three worlds have the utmost, right and perfect enlightenment.
Know then that the Prajna Paramita is the great spiritual mantra, the great radiant mantra, the supreme mantra, the peerless mantra, which removes all suffering, the true, the unfailing. The mantra of the Prajna Paramita is taught, and it is taught thus:
Gone, gone, gone beyond, altogether beyond,
In the Shonankattoroku collection of koans, there is one on this sutra. It runs: What is the one word which contains the whole of the Heart Sutra? Say! (There is a purely philosophical doctrine that the whole of this Sutra can be summed up in the syllable A 5 but this would not be accepted as an answer to the koan.