半畝方塘一鑑開 天光雲影共徘徊
問渠哪得清如許 為有源頭活水來
Insight From Reading Zhu Xi (1130-1200) 江紹倫譯
To the small glassy pond I plunge
To experience how light and shadows play for fun
Asked how ideas in the pond could be so deep and clear
The water comes from bustling springs far and near
What I Learn from Reading a Book Zhu Xi (Southern Song)
Like a mirror opens the half-acre square pond;**
Reflected sunlight, cloud shadows play, stay, and bond.
O, Tell me how can the water be clear like so?
From the source a divine, live fountainhead does flow!
(tr. frank c w yue)
**In ancient China, the mirror was made of polished copper that was reflective and wrapped in a piece of cloth when not in use. Opening a string-bound paper book — that is rectangular or half-square in shape — is like opening up a covered mirror by removing the cloth. The pond (book) of course does reflect the sky (knowledge) and its interaction with the mind (intellectual development).
古人以铜为境，包以镜袱，用时打开。
it appears there’s a typo on the 3rd line of the chinese version
above. it should read “問渠那得清如許，”
Hi Frank,
Thanks for pointing out the mistake.