Yoga Sutras - "Illusory Union"

Could you explain your reference to “illusory union” in your rendition
of the Yoga Sutras of Patanjali? Is it already explained in Chapter 2, sutra
17? Is illusory union dharana, Dhyana and samadhi?

Illusory Union means the false sense of communion of the
inner Self with the mind. When the mind is still present there is illusion.
The pain to be avoided is that caused from instability taking momentary
experiences for being permanent. The True Self is always present. Thus any
momentary experience that gives an exalted state of consciousness is not the
Self. The quest for that causes pain described in the previous sutra II,
16.