take coals to Newcastle

phr

• ① 【口】多此一举;徒劳无功(Newcastle为以多煤著称的一个港口)
  • Mr. Smith is so rich he doesn't need any more money. To give him money is like carrying coals to Newcastle.史密斯先生很富有,他不缺钱用。如果送钱给他,那是多此一举。