"In brief, samadhi is explained
as being the complete satisfaction of the mind.
Great Being, listen attentively
to the explanation of the distinctions:
The samadhi of all the Buddhas
is said to be emptiness by the Jina.
It is attained through complete knowledge of the mind,
and from nothing else.
The complete abandonment of both
is said to be the samadhi of Perfect Buddhas:
It is called the Great Emptiness,
and perfects the All-knowing Awareness.
Therefore you should always recollect
emptiness in all situations."
The Maha-Vairocana-Abhisambodhi Tantra, trans. Stephen Hodge, pp. 123-124.