Book I: Studying 学而第一 Chapter16

子贡曰：“《诗》云：‘如切如磋，如琢如磨’，其斯之谓与？”子曰：“赐也，始可与言《诗》已矣，告诸往而知来者。”

Zigong said, "In the Poetry it says,
         As though cut, as though chiseled,
         As though carved, as though polished.
Is that what you mean?"
The Master said, "Ah, Si! -- I can finally begin to talk about the Poetry with him. I tell him what what came before and he understands what is coming next."