无风不起浪 (wú fēng bù qǐ làng)

无风不起浪

(wú fēng bù qǐ làng)
English Translation:“Without wind, there cannot be waves.”

Meaning:
You can’t have a rainbow without rain. This means that rumors or events often have a source or cause, even if it's not immediately obvious.

Example:
关于他们离婚的消息，有很多人议论，无风不起浪。
(There’s a lot of talk about their divorce; “there can’t be waves without wind.”)

Source: Hello Mandarin