From 《
楚辞·
渔父》(Chu Ci, The Fisherman, ca. 3rd c. BCE). After Qu Yuan declares
举世皆浊我独清, the fisherman smiles, beats his oar, and sings as he rows away:
沧浪之水清兮,
可以濯我缨;
沧浪之水浊兮,
可以濯我足 (When Canglang's water is clear, I wash my hatstrings; when it is muddy, I wash my feet). The fisherman's Daoist rebuttal to Qu Yuan's rigid purity — adapt to the times rather than break against them.