That in which all these worlds seem to exist steadily, that of which all these worlds are a possession, that from which all these worlds rise, that for which all these exist, that by which all these worlds come into existence and that which is indeed all these – that alone is the existing reality. Let us cherish that Self, which is the reality, in the Heart.
How can I attain Self-realisation?
Realisation is nothing to be gained afresh; it is already there. All that is necessary is to get rid of the thought ‘I have not realised’.
Stillness or peace is realisation. There is no moment when the Self is not. So long as there is doubt or the feeling of non-realisation, the attempt should be made to rid oneself of these thoughts. They are due to the identification of the Self with the not-Self.
When the not-Self disappears, the Self alone remains. To make room it is enough that objects be removed. Room is not brought in from elsewhere.
Listen to the 8thC Chinese poet known as Li Po;
“The birds have vanished from the sky,
and now the last clouds slip away.
We sit alone, the mountain and I,
until only the mountain remains.”
First there is a mountain,
then there is no mountain,
then there is.
~ Zen Proverb 
The words of impermanence and perception trace back to Zen scholar Qingyuan Weixin, who explained:
“Before I had studied Zen for thirty years, I saw mountains as mountains, and rivers as rivers. When I arrived at a more intimate knowledge, I came to the point where I saw that mountains are not mountains, and rivers are not rivers. But now that I have got its very substance I am at rest. For it’s just that I see mountains once again as mountains, and rivers once again as rivers.”