Herein, this Lovingkindness Sutta was spoken by the Blessed One, not by disciples, etc.; and that was when bhikkhus, who had been harassed by deities on the slopes of the Himalayas, had gone to the Blessed One's presence; and it was uttered then at Savatthi as a meditation subject with the purpose of [providing] a safeguard for those bhikkhus. That, it should be understood in brief to start with, is how the clarification of the source illustrates those questions.

But in detail it should be understood as follows. On one occasion the Blessed One was living at Savatthi when the [time for the] taking up of the Residence for the Rains was near at hand. Now on that occassion many bhikkhus from various countries, who were desirous of taking up residence for the rains in various places after taking a meditation subject in the in the Blessed One's presence, had approached the Blessed One.

And there he had expounded meditation subjects suitable for the eighty-four thousand shades of temperament in the following way, that is to say: for those of lustful temperament he showed Loathesomeness as a meditation subject of the eleven kinds as with consciousness and without consciousness; for those of hating temperament the fourfold meditation subject beginning with Lovingkindness; for those of deluded temperament, the meditation subject consisting in Mindfulness of Death, etc.; for those of speculative thinking temperament, Mindfulness of Breathing, the Earth Universal, etc.; for those of faithful temperament, the subjects consisting of the Recollections of the Enlightened One, etc.; and for those of intelligent (discovering) temperament, the Definition of the Four Elements.

So when [a party of] five hundred bhikkhus had learnt each a meditation subject in the Blessed One's presence and were seeking a suitable resting place with a village as alms resort, eventually in the outland country they came in sight of a mountain forming part of the Himalaya range. While its surface glittered like blue quartz crystal, it was embellished with a cool dense shady green forest grove and a stretch of ground strewn with sand resembling a net or a silver sheet; and it was furnished with a clean spring of grateful cool water. Now when the bhikkhus had spent one night there and the dawn was drawing near, they attended to the needs of the physical frame and then went for alms into a town not far distant. The town was connected with a thousand clans and constructed as a community-residence, and the people there had faith and confidence.

Since it is hard in the outlands to get a sight of those gone forth into homelessness, they were happy and joyful when they saw the bhikkhus, and they fed them and begged them to stay on for the three months (of obligatory residence during the Rains) and they had five hundred work-rooms built and furnished with all such necessities as beds, chairs, pots for drinking and washing water, and so on. On the following day the bhikkus went into another town for alms, and there too the people served them in like manner and begged them to stay on for the Rains. The bhikkhus consented subject to there being no obstacle. The re-entered the wood, where they [arranged to keep up] energy night and day by having a wood-block struck for the watches, and abiding much in reasoned attention, they went to the roots of trees and sat down.

The tree deities were discouraged by the virtuous bhikkhus’ courage, and they came down from their own mansions and wandered back and forth with their children, just as when a block of houses is commandeered from villagers by kings or royal ministers and the human inhabitants of the houses who have had to evacuate them and go to live elsewhere watch from a distance, [wondering] ' When are the venerable ones going way', so too the deities came down from their own mansions and wandered back and forth, watching from a distance wondering 'When are the venerable ones going away?'. Next they thought thus ' Bhikkhus who enter upon the first period for residence for the Rains will certainly stay on for three months; but we cannot live with our children away from home for so long. Let us show the bhikkhus some object that will scare them away '.

So in the night when it was the bhilkkhus' time to give effect to the monks’ True Ideal, they created terrifying forms of spirits, and standing in front of each of them, they made dreadful noise. When the bhikkhus saw the forms and heard the noise, their hearts quailed, they grew pale and jaundiced and they could no longer unify their cognizance. When they were harassed again and again by this fear, with their cognizance ununified they forgot their mindfulness. As soon as they had forgotten their mindfulness, the deities harassed them with bad smells. Their brains to seemed to smother in the stench, with feelings of oppression in their heads. However, they did not mention their hauntings to each other.

Then one day when all had assembled at the time for waiting on the Senior Elder of the Community, he asked them "Friends, when you first entered into this wood, the color of your skin was quite pure and bright for some days and your faculties were clear; but now you are lean and pale and jaundiced. What does not suit you here?" Then a bhikkhu said 'Venerable sir, at night I saw and heard such-and-such a dreadful object and I smelt such-and-such a smell, and so my mind was not concentrated", and all told in the same way what hadhappened. The Senior Elder said "Friends. two kinds of entry upon Residence for the Rains have been described by the Blessed One, and this resting place does not suit us. So let us go to the Blessed One and ask about another resting place that will suit us."

The others agreed, and so they all put their resting places in order, and then they took their bowls and [outer] robes and without even telling anyone--for they had no attachments among the clans—they set out to wander by stages to Savatthi. They went to the Blessed One. When he saw them, he said ' Bhikkhus, a training rule has been made known by me saying that no one is to go wandering during the Rains. Why are you wandering?

They told the Blessed One all that had happened. The Blessed One adverted to the whole of Jambudipa, but he saw not so much as even a place for a four-legged chair that might suit them as a resting place. Then he told them "Bhikkhus, there is no other resting place that will suit you. It is only by living there that you might reach the exhaustion of taints. So go and occupy that same resting place. But if you want to be free from fear of deities, then learn this safeguard; for this will be both a safeguard and a meditation subject for you," and he uttered this Sutta.

The Origins of the Mettasuttam