The world is the unity of consciousness and its contents
Here, Sam Harris refers to a central aspect of non-duality in the meditator's mind. The practiced meditator is constantly aware of what is known in Tibetan Buddhism as "the inseparable pair".
The inseparable pair is the unity of the inner space (the vast expanse, or mind itself), and the mental events arising in it (thoughts, sensations etc).
The meditator holds both simultaneously in mind, without losing themselves either in the ground (thus becoming drowsy) or being caught up by the stream of events (this becoming excited).
There is also no preference for either. For example, some people may feel more drawn to the experience of space, identifying with it. This is wrong.
The Tibetan writings express this unity in many metaphors.
The left side of the following table represents the ground/space/vast expanse/mind The liveliness aspect. The right side represents the content/event view.
Liveliness of what arises
Energy of what arises
add: emptiness / appearance (Barth)
Masculinity / Femininity as seen by Deida
Just as an aside: while in some Buddhist traditions "pure consciousness" is associated with masculinity, here it is assigned to the feminine (mother) aspect.
Unfortunately, all neo-tantra approaches such as David Deida rest on a different tradition (Shakti/Shiva) without being explicit about the fact that this is an arbitrary choice of the relevant Buddhist tradition.
Brown, D.P., & Thurman, R. (2006). Pointing Out the Great Way: The Stages of Meditation in the Mahamudra Tradition. In No Title (Annotated). Wisdom Publications. https://www.amazon.de/-/en/Daniel-P-Brown/dp/0861713044/
Deida versus Soma: femininity and spirituality (). (2021, June 6). Till Gebel. Retrieved 7 September 2022, from https://www.till-gebel.com/post/deida-shallow-spirituality
Mtshan, S.R.B.S.R., Brown, D. P., & Gurung, S. G. (2022, January 14). Self-Arising Three-fold Embodiment of Enlightenment [of Bon Dzogchen Meditation]. Mustang Bon Foundation. https://www.amazon.com/-/de/dp/1732157944/