Frankly, the way Ajahn chah teach is not a typical Theravada master. His teaching style is very similar to the zen, Mahamudra, Mahasandi style.
Does anyone know whether he has a contact or dharma sharing with other traditions?
Based on what I know is his teaching is coming purely from his meditative insight. He is very seldom quote any Sutta, like what scholars normally do.
THE MIND
About this mind...
In truth there is nothin really wrong with it.
It is intrinsically pure.
Within itself, it's already peaceful.
That the mind is not peaceful these days
is because it follows moods.
The real mind doesn't have anything to it,
it is simply (an aspect of) Nature.
It becomes peaceful or agitated
because moods deceive it.
That gladness or sadness
is not the mind,
but only a mood coming to deceive us.
The untrained mind gets lost
and follows these things,
It forget itself.
Then we think it is we
who are upset or at ease or whatever.
But really this mind of ours is inherently
unmoving and peaceful...
really peaceful!
Just like a leaf which is still
As long as no wind blows.
If a wind comes up, the lead flutters -
The fluttering is due to the wind.
Our 'fluttering' is due to those sense impressions;
The mind follows them.
If it doesn't follow them, it doesn't 'flutter'
If we know fully
the true nature of sense impressions
we will be unmoved.
Our practice is simply to see
the Original Mind.
So we must train the mind
to know those sense impressions, and
not get lost in them.
To make it peaceful.
Thus is the aim
of all this difficult practice
we put ourselves through.