Anicca: Impermanence
Mountains, the very picture of what cannot move, are named here as the things that will depart. Even the hills, which outlast whole peoples, are set to be removed, the way even the oldest tree finally comes down. The most immovable things on earth are held up as examples of what does not stay.
Mettā: Loving-kindness
Against the moving mountains stands a kindness that will not budge. This is warmth steadier than stone, goodwill that outlasts the hills themselves. When the last mountain is gone, it is still there.
Adhiṭṭhāna: Unshakable resolve
The covenant of peace is set as a thing that cannot be removed, a resolve firmer than bedrock. Where the mountains give way, this holds without a tremor. It is a vow planted deeper than the roots of the hills.
Santi: Peace, the quiet of a settled heart
The covenant offered is one of peace, the deep stillness that does not depend on the landscape holding. Mountains may go and this calm remains, resting on nothing that can be shaken. It is the quiet that stays quiet when everything solid moves.