Karaniya Metta Sutta is both a paritta, a protection prayer and
also a contemplative cultivation.
I personally chant this prayer and allow me to cultivate loving
kindness.
I consider this paritta to be simple and yet powerful. When one
is mindful and have loving kindness within one heart, one has a
natural fearlessness.
There are article relating to Karaniya Metta Suttanta. I will
post and provide links when it concurs with my viewpoint.
Unless my memory fails me,
I believe this paritta was taught to monks who were meditating when
they were being disturbed by some forest spirits.
The historical background which led the Buddha to expound
the Karaniya Metta Sutta is explained in the
commentary written by Acariya Buddhaghosa, who received it from an
unbroken line of Elders going back to the days of the Buddha
himself.
It is told that five hundred monks received instructions from the
Buddha in the particular techniques of meditation suitable to their
individual temperaments. They then went to the foothills of the
Himalayas to spend the four months of the rains' retreat by living
a life of withdrawal and intensive meditation. In those days, a
month or two before the rains' retreat started, monks from all
parts of the country would assemble wherever the Buddha lived in
order to receive direct instruction from the Supreme Master. Then
they would go back to their monasteries, forest dwellings or
hermitages to make a vigorous attempt at spiritual liberation. This
was how these five hundred monks went to the Buddha, who was
staying at Savatthi in Jeta's Grove in the monastery built by
Anathapindika.
After receiving instructions they went in search of a suitable
place, and in the course of their wandering they soon found a
beautiful hillock at the foothills of the Himalayas. This,
according to the commentary, "appeared like a glittering blue
quartz crystal: it was embellished with a cool, dense, green forest
grove and a stretch of ground strewn with sand, resembling a pearl
net or a silver sheet, and was furnished with a clean spring of
cool water." The bhikkhus were captivated by the sight. There were
a few villages nearby, and also a small market-town ideal as
alms-resort. The monks spent a night in that idyllic grove and the
next morning went to the market-town for alms.
The residents there were overjoyed to see the monks, since rarely
did a community of monks come to spend the retreat in that part of
the Himalayas. These pious devotees fed the monks and begged them
to stay on as their guests, promising to build each a hut near the
grove on the sandy stretch so that they could spend their days and
nights plunged in meditation under the ancient boughs of the
majestic trees. The bhikkhus agreed and the devotees of the area
soon built little huts in the fringe of the forest and provided
each hut with a wooden cot, a stool and pots of water for drinking
and washing.
After the monks had settled down contentedly in these huts, each
one selected a tree to meditate under, by day and by night. Now it
is said that these great trees were inhabited by tree-deities who
had a celestial mansion built, appropriately using the trees as the
base. These deities, out of reverence for the meditating monks,
stood aside with their families. Virtue was revered by all,
particularly so by deities, and when the monks sat under the trees,
the deities, who were householders, did not like to remain above
them. The deities had thought that the monks would remain only for
a night or two, and gladly bore the inconvenience. But when day
after day passed and the monks still kept occupying the bases of
the trees, the deities wondered when they would go away. They were
like dispossessed villagers whose houses had been commandeered by
the officials of visiting royalty and they kept watching anxiously
from a distance, wondering when they would get their houses
back.
These dispossessed deities discussed the situation among themselves
and decided to frighten the monks away by showing them terrifying
objects, by making dreadful noises and by creating a sickening
stench. Accordingly, they materialized all these terrifying
conditions and afflicted the monks. The monks soon grew pale and
could no longer concentrate on their subjects of meditation. As the
deities continued to harass them, they lost even their basic
mindfulness, and their brains seemed to become smothered by the
oppressing visions, noise and stench. When the monks assembled to
wait upon the seniormost Elder of the group, each one recounted his
experiences. The Elder suggested: "Let us go, brethren, to the
Blessed One and place our problem before him. There are two kinds
of rains' retreat — the early and the late. Though we will be
breaking the early one by leaving this place, we can always take
upon ourselves the late one after meeting the Lord." The monks
agreed and they set out at once, it is said, without even informing
the devotees.
By stages they arrived at Savatthi, went to the Blessed One,
prostrated at his feet, and related their frightful experiences,
pathetically requesting another place. The Buddha, through his
supernormal power, scanned the whole of India, but finding no place
except the same spot where they could achieve spiritual liberation,
told them: "Monks, go back to the same spot! It is only by striving
there that you will effect the destruction of inner taints. Fear
not! If you want to be free from the harassment caused by the
deities, learn this sutta. It will be a theme for meditation as
well as a formula for protection (paritta).
Then the Master recited the Karaniya Metta
Sutta — the Hymn of Universal Love — which the monks
learned by rote in the presence of the Lord. Then they went back to
the same place.
As the monks neared their forest dwellings reciting
the Metta Sutta, thinking and meditating on the
underlying meaning, the hearts of the deities became so charged
with warm feelings of goodwill that they materialized themselves in
human form and received the monks with great piety. They took their
bowls, conducted them to their rooms, caused water and food to be
supplied, and then, resuming their normal form, invited them to
occupy the bases of the trees and meditate without any hesitation
or fear.
Further, during the three months of the rains' residence, the
deities not only looked after the monks in every way but made sure
that the place was completely free from any noise. Enjoying perfect
silence, by the end of the rainy season all the monks attained to
the pinnacle of spiritual perfection. Every one of the five hundred
monks had become an arahant.
Indeed, such is the power intrinsic in the Metta
Sutta. Whoever
with firm faith will recite the sutta, invoking the protection of
the deities and meditating on metta, will not only safeguard
himself in every way but will also protect all those around him,
and will make spiritual progress that can be actually verified. No
harm can ever befall a person who follows the path of
metta.For further
reading:-
http://www.accesstoinsight.org/lib/authors/buddharakkhita/wheel365.html