8 Verses of Mind Training

Compassion is far more than emotion.
It is something which springs
Up in the emptiness which is when
you yourself are not there
So that you do not know anything about it.
Nobody, in fact, knows anything about it.
(If they knew it, it would not be compassion);
But they can only smell
The scent of the unseen flower
That blooms in the heart of the Void.

Sangharakshita, The Unseen Flower