5. Herein, purification should be understood as Nibbána, which being devoid of all stains, is utterly pure. The path of purification is the path to that purification; it is the means of approach that is called the path. The meaning is, I shall expound that path of purification.
6. In some instances this path of purification is taught by insight alone,3 according
as it is said:
“Formations are all impermanent:
When he sees thus with understanding
And turns away from what is ill
That is the path to purity” (Dhp 277).
And in some instances by jhána and understanding, according as it is said:
“He is near unto Nibbána
In whom are jhána and understanding” (Dhp 372).
And in some instances by deeds (kamma), etc., according as it is said:
“By deeds, vision and righteousness,
By virtue, the sublimest life—
By these are mortals purified,
And not by lineage and wealth” (M III 262).
And in some instances by virtue, etc., according as it is said:
“He who is possessed of constant virtue,
Who has understanding, and is concentrated,
Who is strenuous and diligent as well,
Will cross the flood so difficult to cross” (S I 53).
And in some instances by the foundations of mindfulness, etc., according as it
is said: “Bhikkhus, this path is the only way for the purification of beings … for the
realization of Nibbána, that is to say, the four foundations of mindfulness” (D II
290); and similarly in the case of the right efforts, and so on. But in the answer to
this question it is taught by virtue and the other two.
By Bhikkhu Ñānamoli