Yoga and the self

From the introduction to Book 6:

Book 6 continues the theme of renunciation and detachment, indifference and equanimity of mind. We have learned briefly in the previous chapter something of the breath-control techniques of yoga. In this book, beginning at 6:10, we have a short treatise on the techniques of concentration and meditation which continues through to 6:28 and the apotheosis of the self absorbed in brahman. Then, at 6:37, Arjuna raises another doubt. What becomes of the man who makes the attempt to follow the way of yoga and its discipline, but fails to achieve that final goal? The answer comes as a reassurance that no effort is entirely lost. The yogin is reborn and, by cumulative increments over many lifetimes, realises the self. Arjuna is urged, finally, to become this man, a yogin. The very last verse personifies the voice of the united state of brahman-atman, anticipating the change of tone and direction in the Gita that begins with Book 7.

From Book 6:

is the essence of this way.
There is no way
without renunciation
of self-interest.

The wise man 
who desires to find the way
pursues the way of action.
He who has already found it
holds quietly to it.

When not attached
to objects of the senses
or to the objects 
of his actions,
and purposeless,
then it can be said
that he has found the way.

6:10 - 6:15
only on the self,
he sits 
secluded and alone,
his thoughts subdued,
desiring nothing,
possessing nothing.
He firmly sits
in some place clean and pure,
covered first with fragrant grass,
a deerskin, then a cloth,
placed neither high nor low.
Focused on a single point,
subduing thoughts and senses,
he sits
and practices this discipline
to purify the self.
With body, head and neck erect,
motionless he sits,
focused on the point of his nose
and looking nowhere else.
With quietude of mind
and all fears put away
he dedicates himself to abstinence.
His thoughts controlled,
he sits and concentrates
on me alone, the higher self.
And so by constancy
and diligence in practice
he finally subdues the mind
and finds tranquillity and peace
absorbed in me.