鳶飛魚躍
Meanings
all things following their nature and living freely; Heaven's will for free and natural life
A rare yojijukugo expressing the idea that all beings should live according to their innate nature, freely and joyfully. Sense 2 adds a metaphysical dimension of Heaven's will. The literal image is of kites flying and fish leaping.
鳶飛魚躍 is a classical idiom that describes all things living freely according to their original nature.
ruler's benevolence spreading so people find their place
A rare extended meaning: when a ruler's benevolence spreads, people naturally find their proper roles according to their abilities. This sense is more political and less common.
In classical texts, 鳶飛魚躍 can refer to the ideal where, through a ruler's virtue, the people each demonstrate their abilities.