避其銳氣，擊其惰歸 [－－锐气－击－－归]

Jyutping bei6 kei4 jeoi6 hei3 , gik1 kei4 do6 gwai1
Pinyin bì qí ruì qì , jī qí duò guī

Definitions (CC-CEDICT)
  1. avoid the enemy when he is fresh and strike him when he is tired and withdraws (idiom)