What is inspection? It is not to let what one knows slip away from one's mind. Its function is not to be distracted.
It is an awareness which has three specific features:
1. Specific feature of the object -- it is a thing you know
2. Specific feature of the observable quality -- this object is not forgotten
3. Specific feature of the function -- it remains steady
Since inspection does not arise concerning a thing which has not been well known previously, the specific feature of its function is said to deal with something familiar. Since inspection does not operate on an object which does not come to mind at present even though it may have been familiar before, it implies the feature of not letting the object slip out of the mind. On the basis of this special function, the levels of the mind can grow in intensity and this means that mind does not swerve.

The fact that inspection must possess the three specific functions is very improtant whether one deals with the Sutras or Tantras.

The Tathagata has taught that
Inspection belonging to the great beings
Is the only path to walk.
To this hold tight and preserve it.
If inspection slips, everything is lost.
-Nagarjuna (Suhrllekha, 54)
Those who have listened and have confidence
But do not apply assiduous striving
By being attached to the defect of not knowing properly,
Will become soiled by falling away from their status.

Those thieves, the lack of awareness and
The pursuit of that from  which inspection slips,
Not only rob one's wealth and a happy state of existence,
But they also cause one to wander about in evil existences.

These robbers, which are the emotions,
Go about seeking an opporunity.
When they get it, the steal the wholesome
And even destroy life in a good existence.

Therefore, never, never allow inspection
to wander out of the mind's door.
But if by chance it should, then by recalling
Those pains of evil existence, bring it back close to you.

By keeping company with a guru and
By the instructions of the learned,
Those who are pious and pay respect because they are afraid something may go wrong
Will gain inspection which develops the positive.


All values (qualities) inherent in the various levels and paths depend on inspection and awareness. Since any attainment of concentration, be it on the basis of the Sutras or Tantras, must be attained by virtue of this specific function, the application of inspection is very important for those who want to have this experience coming from the bottom of their hearts.

May my possessions, my status,
My body and my life be for nothing!
May even all other wholesome things come to nought!
But, may the mind never be lessened.

To those who desire to guard the mind,
I pray, saying,
"Preserve your inspection and awareness
Even if it costs you your life."