Meditation at the centre of two pillars – with Ali
Today, our meditation borrowed from the Vijñana Bhairava Tantra. Verse 61 is typical of the Trika school, which concentrates on three points to reveal universal truth.
More specifically, when we take any two things or conceptual opposites (such as left-right, up-down), and focus our attention at the centre of these two objects, then relinquish the two supporting objects, a resulting transcendent reality is revealed (tattvaṃ prakāśate).
This centeredness is called madhya.
Accordingly, I focused my awareness on the in-breath flowing down into my spinal base (mūlādhāra), and then on the out-breath flowing up to my crown (sahasrāra). My point of concentration was the midpoint – the heart. I abandoned my base and crown, as focal points, and concentrated exclusively on the heart.
Then, I deepened my heart-centeredness focus by creating another dimension. This time I focused my attention outward on a dear student to my left (who was displaying a degree of mental agitation) and on the rhythmic sound of the omkara – continuous sounding OM to my right. Abandoning both, the insight was that of the peaceful Void (śūnyatā).
Being established in the Void, I closed my eyes and left behind these impressions. What appeared before my eyes was an intense violet light.
I abandoned the violet light and a rod appeared. I abandoned the rod and it became a spiralling helix. I abandoned the spiralling helix is became a tubular flower. I abandoned the cosmic flower and everything became still and black.
I sat peacefully in the universal centre (śāktopāya).
 Swami Lakshman Joo, Vijñana Bhairava: The Practice of Centring Awareness (Varanasi, India: Indica Books, 2007), 82.