This was said by the Blessed One, said by the Arahant, so I have heard:
"There are these three grounds for meritorious activity.
Which three?
The ground for meritorious activity made of generosity, the ground for meritorious activity made of virtue, and the ground for meritorious activity made of development [meditation].
These are the three grounds for meritorious activity."
Train in acts of merit that bring long-lasting bliss — develop generosity, a life in tune, a mind of good-will. Developing these three things that bring about bliss, the wise reappear in a world of bliss unalloyed.
— Iti 60

The Triple Wisdom Preservation Public Talk program consists of seasonal public talks that are open to all in towns and cities across the United States to create real-world opportunities to meet with a serious practitioner of traditional medicine, yoga and other methods from the Buddhist tradition. All talks are also available worldwide on Zoom.

This spring series covers several foundational pillars of the Buddhadhamma - it’s an excellent introduction for newcomers interested to meet with the Dhamma and a profound teaching for established practitioners. The fields of merit are a vast subject in the Pali Canon containing actionable teachings on the conduct of one’s body, speech and mind. Learning the ways in which we can develop ourselves to cultivate merit promotes our journey along the path towards enlightenment.

"Rahula, all those brahmans & contemplatives in the course of the past who purified their bodily acts, verbal acts, & mental acts, did it through repeated reflection on their bodily acts, verbal acts, & mental acts in just this way.
"All those brahmans & contemplatives in the course of the future who will purify their bodily acts, verbal acts, & mental acts, will do it through repeated reflection on their bodily acts, verbal acts, & mental acts in just this way.
"All those brahmans & contemplatives at present who purify their bodily acts, verbal acts, & mental acts, do it through repeated reflection on their bodily acts, verbal acts, & mental acts in just this way.
"Thus, Rahula, you should train yourself: 'I will purify my bodily acts through repeated reflection. I will purify my verbal acts through repeated reflection. I will purify my mental acts through repeated reflection.' That's how you should train yourself."
— MN 61

What does merit mean?

With mind rightly directed,
speaking right speech,
doing right deeds with the body:
a person here
of much learning,
a doer of merit
here in this life so short,
at the break-up of the body,
discerning,
reappears in heaven.
— Iti 71

According to Access to Insight:

Of all the concepts central to Buddhism, merit (puñña) is one of the least known and least appreciated in the West. This is perhaps because the pursuit of merit seems to be a lowly practice, focused on getting and [the self] whereas higher Buddhist practice focuses on letting go, particularly of any sense of self. Because we in the West often feel pressed for time, we don't want to waste our time on lowly practices, and instead want to go straight to the higher levels. Yet the Buddha repeatedly warns that the higher levels cannot be practiced in a stable manner unless they develop on a strong foundation. The pursuit of merit provides that foundation.

… Buddhist wisdom famously focuses in the characteristics of inconstancy, stress, and not-self, but the application of that wisdom grows out of the pursuit of what is relatively constant and pleasant, and requires a mature sense of self: able to plan for the future, to sacrifice short-term happiness for long-term happiness, to consider the needs of others, and to develop a strong sense of self-reliance in the pursuit of a happiness that is wise, pure, and compassionate.

Source: "Merit: A Study Guide", by Thanissaro Bhikkhu. Access to Insight (BCBS Edition), 30 November 2013, http://www.accesstoinsight.org/lib/study/merit.html.

Train in acts of merit
that bring long-lasting bliss —
develop generosity,
a life in tune,
a mind of good-will.
Developing these
three things
that bring about bliss,
the wise reappear
in a world of bliss
unalloyed.
— Iti 22

What does dāna mean?

What the miser fears,
that keeps him from giving,
is the very danger that comes
when he doesn't give.
— SN 1.32

Dāna (giving, liberality; offering, alms).—Specifically, giving of any of the four requisites to the monastic order. More generally, the inclination to give, without expecting any form of repayment from the recipient. Dana is the first theme in the Buddha’s system of gradual training, the first of the ten paramis, one of the seven treasures (see dhana), and the first of the three grounds for meritorious action.

What does silā mean?

Through initiative, heedfulness,
restraint, & self-control,
the wise would make
an island
no flood
can submerge.
— Dhp 25

Virtue, morality. The quality of ethical and moral purity that prevents one from falling away from the eightfold path. Also, the training precepts that restrain one from performing unskillful actions. Sila is the second theme in the gradual training, one of the ten paramis, the second of the seven treasures (see dhana), and the first of the three grounds for meritorious action.

What does bhāvanā mean?

This is to be done by one skilled in aims
who wants to break through to the state of peace:
Be capable, upright, & straightforward,
easy to instruct, gentle, & not conceited,
content & easy to support,
with few duties, living lightly,
with peaceful faculties, masterful,
modest, & no greed for supporters.
Do not do the slightest thing
that the wise would later censure.
Think: Happy, at rest,
may all beings be happy at heart.
Whatever beings there may be,
weak or strong, without exception,
long, large,
middling, short,
subtle, blatant,
seen & unseen,
near & far,
born & seeking birth:
May all beings be happy at heart.
Let no one deceive another
or despise anyone anywhere,
or through anger or irritation
wish for another to suffer.
As a mother would risk her life
to protect her child, her only child,
even so should one cultivate a limitless heart
with regard to all beings.
With good will for the entire cosmos,
cultivate a limitless heart:
Above, below, & all around,
unobstructed, without hostility or hate.
Whether standing, walking,
sitting, or lying down,
as long as one is alert,
one should be resolved on this mindfulness.
This is called a sublime abiding
here & now.
Not taken with views,
but virtuous & consummate in vision,
having subdued desire for sensual pleasures,
one never again
will lie in the womb.
— Khp 9

When we translate bhāvanā, several words are often used to encompass the meaning of the Sanskrit word. “Mental cultivation,” “development” and “meditation” give us an idea to the quality and characteristic of this word. Bhāvāna is the third of the three grounds [or fields] for meritorious action.

Looking further into Bhāvāna, we find two distinctions:

the development of tranquillity (samatha-bhāvanā), i.e. concentration (samādhi), and
development of insight (vipassanā-bhāvanā), i.e. wisdom (paññā).

(Source: Pali Kanon: Manual of Buddhist Terms and Doctrines)

He has gone

beyond attachment here

for both merit & evil —

sorrowless, dustless, & pure:

he's what I call

a brahman.

— Dhp 412

Evil is done by oneself,
by oneself is one defiled.
Evil is left undone by oneself,
by oneself is one cleansed.
Purity & impurity are one's own doing.
No one purifies another.
No other purifies one.
— Dhp 165