賣仔莫摸頭 [卖－－－头]

Jyutping maai6 zai2 mok6 mo2 tau4
Pinyin mài zǐ mò mō tóu

Definitions (CC-CANTO)
  1. one should be resolute (harden their hearts) and be willing to let go once they have decided on something (especially when compelled by circumstances) and not allow themselves any chance to renege