三天不打，上房揭瓦 [－－－－－－－－－]

Jyutping saam1 tin1 bat1 daa2 , soeng6 fong4 kit3 ngaa5
Pinyin sān tiān bù dǎ , shàng fáng jiē wǎ

Definitions (CC-CEDICT)
  1. three days without a beating, and a child will scale the roof to rip the tiles (idiom)
  2. spare the rod, spoil the child