ㄧㄤˊㄇㄠˊyángmáoㄔㄨchūㄗㄞˋzàiㄧㄤˊyángㄕㄣㄕㄤ˙shēnshang

  1. 比喻獲取利益事實本身 羊毛出在羊身上受騙沾沾自喜」。

lit. wool comes from the sheep's back (idiom)​; One gets the benefit, but the price has been paid., Nothing comes for free.
(expr. idiom.)​ la laine de mouton provient du dos du mouton, rien n'est gratuit