Tao Te Ching · Ch. 15

古之善為士者,微妙玄通,深不可識。夫唯不可識,故強為之容:豫兮若冬涉川;猶兮若畏四鄰;儼兮其若客;渙兮若冰之將釋;敦兮其若樸;曠兮其若谷;混兮其若濁。孰能濁以靜之徐清?孰能安以動之徐生?保此道者,不欲盈。夫唯不盈,故能蔽而新成。

Gǔ zhī shàn wéi shì zhě, wēi miào xuán tōng, shēn bù kě shí. Fú wéi bù kě shí, gù qiǎng wéi zhī róng: Yù xī ruò dōng shè chuān; Yóu xī ruò wèi sì lín; Yǎn xī qí ruò kè; Huàn xī ruò bīng zhī jiāng shì; Dūn xī qí ruò pǔ; Kuàng xī qí ruò gǔ; Hùn xī qí ruò zhuó. Shú néng zhuó yǐ jìng zhī xú qīng? Shú néng ān yǐ dòng zhī xú shēng? Bǎo cǐ dào zhě, bù yù yíng. Fú wéi bù yíng, gù néng bì ér xīn chéng.

The ancient masters of the Tao were subtle, mysterious, penetrating, and too deep to be known. Because they cannot be known, we can only attempt to describe their appearance: cautious, like one crossing a river in winter; alert, like one wary of neighbors on all sides; courteous, like a guest; yielding, like ice about to melt; simple and solid, like an uncarved block; open and vast, like a valley; turbid and murky, like muddy water. Who can let turbid water slowly settle into clarity? Who can let the still slowly stir into life? One who keeps this Tao does not wish to be full. Because he is not full, he can renew himself without exhausting what is worn.

— Tao Te Ching 15

Source: Wang Bi edition (Chinese) + Hanyu Pinyin transliteration