From
《道德经》 (Daodejing / Tao Te Ching) chapter 8, by Laozi (
老子). Full passage:
『上善若水。
水善利万物而不争,
处众人之所恶,
故几于道』 - 'the highest good is like water: it benefits all things and contends with none, settling in places people disdain - so it is close to the Dao.' The chapter is the source of the idiom
上善若水.