兄弟鬩於墻，外禦其侮 [－－阋于墙－－御－－]

Jyutping hing1 dai6 jik1 jyu1 coeng4 , ngoi6 jyu6 kei4 mou5
Pinyin xiōng dì xì yú qiáng , wài yù qí wǔ

Definitions (CC-CEDICT)
  1. internal disunity dissolves at the threat of an invasion from outside (idiom)