一言九鼎

one word worth nine sacred tripods (idiom); words of enormous weight

one / single / a (article) / as soon as / entire; whole; all; throughout / "one" radical in Chinese characters (Kangxi radical 1) / also pr. [yao1] for greater clarity when spelling out numbers digit by digit

one sentence / brief remark

words / speech / to say / to talk

nine / 9

the Nine Tripod Cauldrons, symbol of state power, dating back to the Xia Dynasty

ancient cooking cauldron with two looped handles and three or four legs / pot (dialect) / to enter upon a period of (classical) / Kangxi radical 206 / one of the 64 hexagrams of the Book of Changes