As wood grows straight by the chalk line and metal sharpens on the stone, young people must dare to face hardship.
Tips
history
From Xunzi's (荀子, Warring States) 《荀子·劝学》 ('Encouraging Learning'): 木受绳则直，金就砺则利，君子博学而日参省乎己 - 'wood is straightened by the chalk line, metal is sharpened by the whetstone; the noble one studies widely and daily examines himself.' A foundational statement of Confucian self-cultivation.
usage
Always quoted in parallel with 木受绳则直. 就 here means 'to go up to / be applied to,' and 砺 (lì) is the coarse whetstone - different from 利 (sharp), which is the result.
