The Secret Key to the Heart Sutra: Invocation

The Heart Sutra is a relatively short sutra with a length of roughly 270 characters-- making it ideal for both recitation and reproduction (both acts produce unmeasurable amounts of good). Furthermore, the Heart Sutra is one of the foundational sutras for nearly every denomination, sect and lineage of Mahayana Buddhism and this is true for Japanese Buddhism as well.

According to Kukai, Buddhism exists in two forms-- the Esoteric and Exoteric. Exoteric Buddhism depends almost exclusively on the literal interpretation of Buddhist sutras and, therefore, asserts limited access to Ultimate Enlightenment. In contrast, Esoteric Buddhism is concerned with tapping into the unlimited compassion available to us at any moment and achieving Enlightment, now, in this very body, and not in thousand or hundred or even one more rebirth. In other words, Esoteric Buddhism is about creating pathways to instant Enlightenment. Enlightenment as the Buddha did-- now and not later.

Kukai's categorization of Buddhism led to a debate over not only which lineages and teachings were Esoteric but over which sutras were Esoteric. As a part of this debate, it became necessary to clarify which type of sutra the Heart Sutra was. In the Secret Key to the Heart Sutra, Kukai not only claims the Heart Sutra as an Esoteric Sutra but goes on to explain his reasons for coming to that conclusion.

The Opening Invocation to the Secret Key to the Heart Sutra.

Classical Chinese Original

文殊利剣絶諸戯
覚母梵文調御師
Dhih Mam真言為種子
含蔵諸教陀羅尼
無辺生死何能断
唯有禅那正思惟
尊者三摩仁不譲
我今讃述垂哀悲

Classical Japanese

文殊の利剣は諸戯を絶つ
覚母の梵文は調御の師なり
Dhih Mam真言を種子とす
諸教を含蔵せる陀羅尼でなり
無辺の生死をばいかんがよく断つ
ただ禅那と正思惟とのみあってす
尊者の三摩は仁ゆずらず
われいま讃述す、哀悲を垂れたまえ

Modern Japanese

文殊菩薩が手にしている鋭剣はもろもろの言葉による煩悩を断ち切ってくれる。
般若菩薩が手にしているインドの経典は煩悩を鎮める師である。
それらの二菩薩を表す種子はそれぞれDhih とMamである。
この梵字はあらゆる教えが含まれている陀羅尼である。
限りのない生と死を、どのように断つことができようか。
それには、ただ禅定と正しい智慧があってこそ（可能となるのである）。
尊者の悟りの境地を、みほとけはお説きになった。
私は、いまからそのことを説き示そう。みほとけよ、どうか御慈悲たまわらんことを。

English Translation

Manjusri's razor-sharp sword brings an end to unfounded speculations.
The sutras of Prajna are the teachers of self-mastery.
These two Bodhisattvas are expressed by the seed mantras Dhih and Mam.
These two Sanskrit dharani are infused with myriad teachings.
How can one free themselves from the endless cycle of becoming and dying?
There is only one way-- through meditation and the attainment of true wisdom.
The Buddha expounded upon the nature of Enlightenment.
May I have the Buddha's compassion as I attempt to explicate this Enlightenment herein.