To jump the gun is to do something too soon.

To jump the gun。 To jump就是“跳高”或“跳跃”的“跳”。

youdao

Boss: Don't jump the gun. We need a further discussion.

老板：不要草率行事，我们还需要作进一步讨论。

youdao

Whoa! Let's not jump the gun. This is only our first date.

哇！我们别这么早就打如意算盘。这才是我们第一次约会而已。

youdao

At least from what I saw Tuesday night, networks did not jump the gun on calling any states before they were closed.

NPR: Media Report Election With Restraint �� And A Wink

People should not "jump the gun" over whether or not the UK's Trident nuclear weapons system is to be replaced, says Deputy Prime Minister Nick Clegg.

BBC: UK Politics

Did the RBA jump the gun with its rate cut?

FORBES: Choked By Options, The Euro Eases As It Awaits A Catalyst