The Heart Sutra has continued to vex me since I’ve first heard it. And the reason is emptiness.
The dictionary says emptiness is:
the state of containing nothing.
“the vast emptiness of space”
the quality of lacking meaning or sincerity; meaninglessness.
“he realizes the emptiness of his statement”
But in the Mahayana tradition, emptiness is Sunyata, which refers to the tenet that “all things are empty of intrinsic existence and nature”.
“Body is nothing more than emptiness,
emptiness is nothing more than body.
The body is exactly empty,
and emptiness is exactly body.
The other four aspects of human existence —
feeling, thought, will, and consciousness —
are likewise nothing more than emptiness,
and emptiness nothing more than they.
All things are empty:
Nothing is born, nothing dies,
nothing is pure, nothing is stained,
nothing increases and nothing decreases”
From the Heart Sutra, http://webspace.ship.edu/cgboer/heartsutra.html