Avera: Freedom from enmity
Avera is hostility laid down on both sides. A fence would only hold the teeth back; a covenant of peace takes the hunger out of the field, so that nothing in it is hunting anything else. The daily wish, may all beings be free from enmity, is that same covenant cut down to a size one person can keep.
Nīvaraṇa: The hindrances
The five hindrances are the mind's own predators: wanting, ill will, dullness, restlessness, doubt. Evil animals ceasing out of the land is what happens inwardly when these five stop circling the herd at dusk and grazing becomes possible again. A flock is scattered by wolves from outside and a mind is scattered the same way from within, so the clearing of the land has to reach that far in.
Mettā: Loving-kindness
Mettā is goodwill sent out without picking favorites. Forest monks were taught to spread it toward snakes and every creature with two feet or four before lying down, and its promised fruit is plain: you sleep well, wake well, and have no bad dreams. Sleeping in the woods follows from goodwill more than from courage, since when nothing in you is at war with the animals, the woods stop being an enemy camp.
Viveka: Seclusion
Viveka is the quiet of an out of the way place, a root of a tree or an empty hut. Wilderness and woods were where the scattered sheep had ended up by accident, hunted and lost, and now the same ground is handed back to them as somewhere to lie down. Monks walk out to that ground on purpose, because open country away from the crowd is the easiest place to see a mind clearly.
Khema: Safety, sanctuary
Khema is security, the word used for a pasture with no wolves in it and for nibbāna alike. Dwelling securely means more than surviving this month's raid; it means standing where raids do not reach. Sleep is the test of it, since an animal only lies down flat where nothing is coming for it, and that is what is being offered to people worn out by shepherds who had been feeding themselves.