Jump the gun

To act prematurely or start something before the proper time, often leading to mistakes or embarrassment due to impatience or misjudgment. It implies a need for restraint, highlighting how haste can undermine success.

This idiom stems from track and field events in the late 19th century, where a starter's gun signaled the beginning of a race. Runners who 'jumped' before the shot risked disqualification-thus, 'jumping the gun' became shorthand for starting too early. It first appeared in sports contexts around the 1890s, with broader use in English by the 1920s, as documented in American newspapers. The phrase reflects the growing popularity of organized athletics and the cultural emphasis on rules and fairness, later expanding into a metaphor for any premature action.