“In order to clearly experience this state devoid of all thoughts, it is necessary to practice and recognize the space between thoughts. Then you have to practice for weeks, months, and years to be familiar with the empty clarity of mind."
[Lopön Tenzin Namdak RInpoche - (extracts) commentary from The Three Precepts: From the Oral Transmission of the Great Perfection in Zhangzhung transl. Jean-Luc Achard]
To return to destiny, one has to empty the mind (Xin) and to keep the heart (Xin) still. (Laozi – Tao Te Ching)
Emptying the mind takes a shorter time and is easier to achieve compared to keeping the heart still. Therefore masters would probably rather concentrate on teaching how to empty the mind during meditation than teach how to keep the heart still. Yet often times they do not discuss how to make an empty mind possible.
A mind is empty when there are no thoughts. But thoughts continuously flow in and out whether one thinks or not. Therefore I have previously indicated that those Chan Buddhists who only concentrate on contemplation during meditation will clutter the mind and not empty it.
To practice and recognize the space between thoughts – to empty the mind – is a good suggestion by the accredited venerable Buddhist Tibetan master and teacher. However students may not quite get it – since the practice is not elaborated on, and is there really a space between thoughts? Therefore it can lead to confusion and pages of online forum discussion – with some suggesting ‘aiming at the space between thoughts’.
‘Aiming at the space between thoughts’ is of course off the target. That is not the way, and can lead to bypaths – visualizations or even delusions - if students are not careful, whether or not they are taught by teachers.
Since thoughts continuously flow in and out there is no need for an ‘artificial separation’ to create a space between them. And one cannot expand the space between thoughts - that is like separating the sea (of thoughts) to create a path!
Seeing where thoughts come in and where they leave is good enough according to Lu Dongbin in the Secret of the Golden Flower. There is no need to find the origin of a thought; for it is impossible to do so according to the divinity.
We should not aim at the space between thoughts, nor artificially create a space or a larger one between thoughts. Do not play games with the mind; it can lead to illusions and/or delusions.
When no more thoughts flow in after thoughts had flowed out, the mind is empty. Then there is that space between thoughts, so to speak.
Everything is natural in neidan (inner alchemy) meditation. With the correct practice, it just takes time and effort. Even for achieving spiritual clarity (Shen Ming).
Meanwhile focusing on the breath will do.