Peaceful is their mind, peaceful their speech and actions. Such is one liberated by true knowledge, the peaceful, the equanimous.

Santaṃ tassa manaṃ hoti — peaceful is their mind: santa (peaceful, at peace) is the root of santi (peace). The peace of the arahant begins in the mind and expresses itself outward naturally, not by effort but by nature.

Santā vācā ca kamma ca — peaceful their speech and actions: the trinity of mind, speech and actions. Inner tranquility inevitably manifests outward. It cannot be simulated because it comes from within.

Sammadaññā vimuttassa — liberated by true knowledge: sammā-aññā is liberating gnosis. Not just knowing that things are impermanent but having realized this so deeply that attachment can no longer establish itself.

Upasantassa tādino — the peaceful, the equanimous: upasanta is profoundly calmed, like a fire extinguished. Tādin is one who is “such” — the technical term for perfect equanimity. Peaceful mind, peaceful speech, peaceful actions: the Trinity of peace.