空穴来风未必无因
kōng​xué​lái​fēng​wèi​bì​wú​yīn

no smoke without fire

  1. 空穴来风 空穴來風 kōng​xué​lái​fēng
    having a factual basis
    (idiom, original meaning) rumors or claims that have a specific reason or basis behind them, just as wind finds a hole to blow through
  2. 未必 wèi​bì adverb
    not necessarily
    not necessarily; may not; indicates that something is not certain to be true or happen
  3. 无因 無因 wú​yīn
    without reason
    (literary) without cause; for no reason