A rotten piece of wood cannot be carved; a wall of dung cannot be plastered.
Tips
history
杇 is not used independently in modern Chinese. It is best known from the Analects line 粪土之墙不可杇也 (a wall of dung cannot be plastered). It joins the wood radical 木 (the wooden trowel handle) with the phonetic 亏 (traditional 虧).
register
Classical and literary only; encountered in old texts and etymology notes, not in modern speech or writing.
