三日不讀書，面目可憎 [－－－读书－－－－－]

Jyutping saam1 jat6 bat1 duk6 syu1 ， min6 muk6 ho2 zang1
Pinyin sān rì bù dú shū ， miàn mù kě zēng

Definitions (Wiktionary)
  1. proverb
    If you are not diligent in your studies, you will remain ignorant, and nobody will be attracted to you.