老鼠拉龜，無從下手 [－－－龟－无从－－]

Jyutping lou5 syu2 laai1 gwai1 , mou4 cung4 haa6 sau2
Pinyin lǎo shǔ lā guī , wú cóng xià shǒu

Definitions (CC-CEDICT)
  1. like mice trying to pull a turtle, nowhere to get a hand grip (idiom)
  2. no clue where to start