At the very beginning of the writings of Mencius, in a chapter on King Hui of Liang, it says that King Wen had a lake dug where the fish could swim about freely and the king and people could enjoy the natural setting.
《孟子》梁惠王第二章就說「王在靈沼，於牣魚躍」，文王蓋了「養魚池」，與民同樂，樂有糜鹿魚鱉。