蓬生麻中，不扶而直 [－－－－－－－－－]

Jyutping pung4 sang1 maa4 zung1 ， bat1 fu4 ji4 zik6
Pinyin péng shēng má zhōng ， bù fú ér zhí

Definitions (Wiktionary)
  1. proverb
    one can become a good person by being in a good environment