Impermanence

Sabbe sankhara anicca'ti;
yada pannaya passati,
atha nibbindati dukkhe,
esa maggo vissuddhiya.

- Dhammapada - 277.

Impermanent are all compounded things. (conditionings)
When one perceives this with true insight,
one becomes detached from suffering;
this is the path of purification.