涅槃經遊意 1.53

1.53

無常為「半」，常為「滿」，別二邊高下。若非常非無常，常無常具足，別二邊雙遊也。

Impermanence being "half" and permanence being "full" distinguishes the hierarchy of the two extremes. If neither permanence nor impermanence and permanence and impermanence are both complete, it distinguishes traversing both extremes simultaneously.