Saṃsāra: Wandering on
Saṃsāra is the round of birth and death, and the word itself means roaming. Riders who cross the whole earth and come back with news have moved without arriving; the circuit closes where it opened, at the feet of the one who sent them. Beings walk that same back and forth for lifetimes, changing the scenery and never changing position, like someone pacing a long hallway who keeps returning to the same door.
Dukkha: Unsatisfactoriness
Dukkha is the ache running through conditioned things. A report of quiet across the whole earth still leaves the broken walls standing and the people far from home, so the calm is a surface reading and nothing more. A house can look fine from the street while water comes steadily through the roof, and that is how things look to a patrol that only counts armies.
Anicca: Impermanence
Anicca is the passing away built into everything formed. Empires at rest are empires between wars, and the same riders sent out in another year would come back with smoke to describe. Peace that rests on nobody happening to march this season is weather: clear this morning, and the sky already changing by evening.
Santi: Peace
Santi is the peace of a mind whose fires have gone out. The stillness the horsemen bring word of is only the absence of trouble on the roads, a hush any raiding party could break by morning. Peace worth the name leans on nothing outside itself, which is why a person can carry it through a burning city while a whole quiet earth has none of it.
Appamāda: Heedfulness
Appamāda is staying awake at your post. One figure stands still among the myrtle trees while the horses run the world, and the standing is the work: hearing that everything is at rest and refusing to be lulled by it. A night watchman is needed most on the quiet nights, when nothing at all seems to require him.