About 2500 years ago Avalokitesvara dictated the heart-sutra to Sariputra, that began with:
Oh, Sariputra, form is emptiness and emptiness is form.
This thesis is the key to the gateless gate.
If everything that we consider as form to not be emptiness and that we con-sider as emptiness to not be form, then we consider form and emptiness as two separate phenomena.
Turning the key is to realize that what we see as separate phenomena is unity.
At the moment that form and emptiness are experienced in their actual quality, this unity cannot be given a name. Our capacity for reasoning is able to ex-press this unity neither in speech, nor in writing, nor in an image, for the simple reason that whoever experiences it themselves is this unity, i.e. speech which explains itself, or an eye that sees itself.
Everything that can be said about it is that you are a you, a tree is a tree, in short, that which is, is.
Hongaku Zeshin
Leiden
29 april 1997