來者不善，善者不來 [来－－－－－－－来]

Jyutping loi4 ze2 bat1 sin6 , sin6 ze2 bat1 loi4
Pinyin lái zhě bù shàn , shàn zhě bù lái

Definitions (CC-CEDICT)
  1. He who comes is surely ill-intentioned, no-one well-meaning will come (idiom).
  2. Be careful not to trust foreigners.
  3. Beware of Greeks bearing gifts!