Where did the phrase "beat it" come from?

Question

used in asking someone to leave?

Answer 1

Not really sure but perhaps it comes from "to beat the retreat", to perform the military ceremony (beating the retreat) consisting of marching and military music, usually performed at dusk, originally marking the recall (by drum beat) of troops to their quarters.

Or from "beat the rap": slang, originally US;  to escape without punishment.

Answer 2

Michael Jackson.

Answer 3

A commonly used cliche variant of 'beat a retreat'. The earliest printed citation is from The Times, October 1827 (reprinted from the Kentish Gazette):