FIVE METHODS OF EXPELLING EVIL THOUGHTS

If, whilst regarding a certain object, there arise in the
disciple, on account of it, evil and demeritorious thoughts
connected with greed, anger and delusion, then the disciple should, by
means of this object, gain another and wholesome object. Or, he should
reflect on the misery of these thoughts: "Unwholesome, truly, are
these thoughts! Blameable are these thoughts! Of painful result are
these thoughts!" Or, he should pay no attention to these thoughts. Or,
he should consider the compound nature of these thoughts. Or, with
teeth clenched and tongue pressed against the gums, he should, with
his mind, restrain, suppress and root out these thoughts; and in doing
so, these evil and demeritorious thoughts of greed, anger and delusion
will dissolve and disappear; and the mind will inwardly become settled
and calm, composed and concentrated.
This is called the effort to overcome.
What, now, is the effort to Develop? There the disciple incites
his will to arouse meritorious conditions that have not yet arisen;
and he strives, puts forth his energy, strains his mind and struggles.
Thus he develops the "Elements of Enlightenment," bent on
solitude, on detachment, on extinction, and ending in deliverance,
namely: Attentiveness, Investigation of the Law, Energy, Rapture,
Tranquility, Concentration, and Equanimity. This is called the
effort to develop.
What, now, is the effort to Maintain? There, the disciple incites
his will to maintain the meritorious conditions that have already
arisen, and not to let them disappear, but to bring them to growth, to
maturity and to the full perfection of development; and he strives,
puts forth his energy, strains his mind and struggles.
Thus, for example, he keeps firmly in his mind a favorable object of
concentration that has arisen, as the mental image of a skeleton, of a
corpse infested by worms, of a corpse blue-black in color, of a
festering corpse, of a corpse riddled with holes, of a corpse
swollen up.
This is called the effort to maintain.
Truly, the disciple who is possessed of faith and has penetrated the
Teaching of the Master, he is filled with the thought: "May rather
skin, sinews and bones wither away, may the flesh and blood of my body
dry up: I shall not give up my efforts so long as I have not
attained whatever is attainable by manly perseverance, energy and
endeavor!"
This is called right effort.

The effort of Avoiding, Overcoming,
Of Developing and Maintaining:
These four great efforts have been shown
By him, the scion of the sun.
And he who firmly clings to them,
May put an end to all the pain.