Found this article very good... and Thusness did an explanation
for me too 
A hint... this yogi has a sincere mind but was deluded by
dogmatism.. (having ideas of preconceived ideas of 'purity' and
'impurity') and did not understand non-duality and emptiness. Thus
Milarapa is pointing out what is the essence of emptiness is form.
For a true yogi, he remains fully engaged in the myriad of
activities and experiences of daily lives -- thoughts still flow,
still there is engagement of pleasure, he sees with clarity
pleasure, but also knows it is empty.
Thusness says: this is like what i told jonls, the transients are
the buddha nature
AEN says: icic..
Thusness says: so what is the difference?
Thusness says: thoughts still flow
Thusness says: still there is engagement of pleasure
Thusness says: but what is the difference?
AEN says: its true nature is comprehended? like u said transience
is buddha nature
Thusness says: what is it?
AEN says: luminous emptiness?
Thusness says: u only see in terms of definition
Thusness says: but milarepa see the actuality of experience
Thusness says: that is he will not see emptiness only
Thusness says: he sees thoughts
Thusness says: not emptiness
AEN says: oic..
Thusness says: but know it is empty
Thusness says: he sees with clarity pleasure
Thusness says: but know it is empty
AEN says: icic..
Thusness says: that is emptiness is form
AEN says: oic
Thusness says: non-duality the last part
AEN says: which one
Thusness says: The Buddhas own
hands couldnt block the appearance of objects to the
consciousness;
A great yogi knows there is no object behind the
appearance.
Next are the insights that a practitioner has to experience/realise
(the four yogas)... spontaneity.. non-conceptuality/blissfulness
free from constructs... non-duality/one-taste... non-meditation..
Thusness too did indepth explanation for me.
Here's the article I'm talking about:
http://www.likeanillusion.com/milarepa-mahamudra.shtml
Milarepa's Mahamudra
Namo guru! After a stay at White Rock Vajra Fortress Cave, the
Jetsun Milarepa settled at Horse Saddle Cave to enhance his
practice. A tantric yogi from Gutang, feeling a tremendous faith
for the Jetsun, went to see him.
Lama, said the yogi, Ive meditated for some years, but I dont
think I got the point. Ive hardly developed any qualities. So
would you please give me an oral instruction?
Heres everything you need to know replied Milarepa. And he sang
the Song of Six Essential Points:
Mental projections way outnumber
the dust motes you see in the sunlight;
A great yogi knows what appears for what it is.
At bottom, the nature of things isnt a product of causes, nor of
conditions
A great yogi cuts to the core of the issue.
Even a hundred men with spears couldnt stop the thought-bubbles of
consciousness;
A great yogi knows not to get hung up on them.
You cant lock up the flow of mind in an iron box;
A great yogi knows mind to be intrinsically empty.
Wisdom gods and goddesses dont say no to sensory pleasures;
A great yogi knows this full well.
The Buddhas own hands couldnt block the appearance of objects to
the consciousness;
A great yogi knows there is no object behind the
appearance.
Do such experiences come about step by step? asked the yogi. Or
is it all at once? Skilled individuals get it at once, answered
Milarepa. It comes more gradually for those of average and
mediocre abilities. Some develop definitive realization, others
dont, and others still get signs that look like realization, but
arent really. And he sang the song of distinguishing the four
yogas:
I bow down at the feet of the
supreme lama!
Its the mind fixated on objects that causes samsara.
If you recognize as spontaneous
The luminous self-awareness, free of fixation,
Youll taste the fruit of the first yoga, one-pointedness.
Some talk and talk about union, yet their meditation is all
conceptual,
They talk and talk about cause and effect, yet their actions are
flawed,
Such petty, deluded meditations
Have no place in the yoga of one-pointedness.
Luminous mind itself, free of fixation,
Is naturally blissful, without constructs.
If you recognize your very essence to be as clear as space,
Youll taste the fruit of the second yoga, simplicity.
Some talk and talk about no elaboration, but they elaborate
plenty,
They talk and talk about the inexpressible, but theyve got
plenty of terminology.
Such self-obsessed meditations
Have no place in the yoga of simplicity.
In the dharma body, appearance and emptiness are not two,
Samsara and nirvana are experienced as one.
If you know the Buddha and sentient beings to have the same
identity,
As many have said: thats definitely the third yoga,
one-taste.
Some talk and talk about oneness, but they still want to make a
point.
Such hazy confusion
Has no place in the yoga of one-taste.
Conceptual thoughts are in nature great awareness;
Cause and effect are non-dual, spontaneous.
Theyre the three bodies,
And knowing this is the fruit of the fourth yoga,
non-meditation.
Some talk and talk about non-meditation, but how active their mind
is!
They talk and talk about clear light, but how thick their
meditation is!
Such platitudes
Have no place in the yoga of non-meditation.
Oh, what wonderful advice! exclaimed the yogi from Gutang.