功莫大焉

gōngmòdàyān
no greater contribution has been made than this (idiom)

CEDICT

Entry Composition

1 功 gōng
  1. meritorious deed or service
  2. achievement
  3. result
  4. service
  5. accomplishment
  6. work (physics)
2 莫大 mòdà
  1. greatest
  2. most important
3 焉 yān
  1. where
  2. how