chǔ

chǔ

pestle / to poke

móchǔchéngzhēn

to grind an iron bar down to a fine needle (idiom); fig. to persevere in a difficult task / to study diligently

xuèliúpiāochǔ

enough blood flowing to float pestles (idiom); rivers of blood / blood bath

zhǐyàogōngfushēn,tiěchǔmóchéngzhēn

If you work at it hard enough, you can grind an iron bar into a needle. / cf idiom [[磨杵成針|磨杵成针]], to grind an iron bar down to a fine needle (idiom); fig. to persevere in a difficult task / to study diligently