I acknowledge this graphic of Sri Chakra Yantra from the Net
In this 66th & 67th verse and dharana technique from Vigyana Bhairava Tantra Shiva says:
Repeating sound of Aaah
Without visarga and bindu
Let the wisdom of Shiva reveal
The mind with visarga
Attains Shiva state
Not being a Sanskrit scholar, my understanding of of bindu and visarga can be challenged.
Akaara, the first letter of the Sanskrit alphabet, and for that matter in most language alphabets I know of (alphabets presumably coming from alpha the first and beta the second letter of the Greek language), is rightly considered the starting point in any learning. It is also the first syllable of the mantra Aum, and represents according to Mandukya Upanishad the first level of consciousness of the gross body or awake state.
The bindu is the dot that appears on top of letters, to produce an ‘N’ or ‘M’ sound. The visarga, in Sanskrit, comprises two dots as in a colon, aspirated and comes at the end of words. In that sense, it can be considered the end point. It can also be looked at as two bindus put together, one top of another.
However, in tantric tradition, these words have additional meaning. Bindu also means ‘seed’. It is the energy center or chakra, between the third eye or ajna and the crown sahasrara. signifying the last point in transit to fulfillment. It’s also associated with the mantra Aum, as the curved dot on top and the final near silent aspiration of extended ‘mmm’. It represents, according to Mandukya Upanishad, the Fourth State of consciousness, the Samadhi state of yoga. It is the central theme in many yantras, including the ultimate Sri Chakra. Those who wih more details can refer to http://www.swamij.com/bindu.htm.
There is a beautiful explanation for the first dharana verse by Laxman Joo. Many mantras end with ah with a visarga or am with a bindu. When the mouth is opened without the visarga or bindu what’s produced is the sound of akara. He says this is cakita mudra, one that naturally produced when one sees a terrifying object such a lion at close quarters. He says that going into and staying in the cakita mudra produces the Shiva state.
The second dharana too is explained beautifully by Joo. He explains that the visarga cannot really be pronounced. It is the unpronounceable sound, unless supported by another word such as ‘a’. When the mind is forced to think of this word and create a sound, it is foxed and becomes still. It’s like a Zen Koan that leads to enlightenment.
Brilliant! First, Shiva tells us to focus on the ‘a’ sound without adding ‘m’ or ‘h’ to it as bindu or visarga. Though difficult, this can be done. Then he says to focus on the visarga ‘h’ without any other word added to it. In Sanskrit grammar, as well as in practical terms, this is impossible, and stills the mind.
These are not dharanas I have practised. I was not satisfied with the explanation from my usual reference of The Ascent, and it took time to locate my copy of Laxman Joo, but it was worth the effort. The concept of these two dharanas, based on the linguistic elegance of Sanskrit fascinated me.