Beforehand
来自Big Physics
Middle English (originally as two words): from before + hand; probably influenced by Old French avant main .
wiktionary
From Middle English biforhand, biforhond, beforehonde, bifornhand, equivalent to before + hand. [13th century. After Old French avant main]
etymonline
beforehand (adv.)
also before-hand, "in anticipation," early 13c., from before + hand, which here is of uncertain signification, unless the original notion is payment in advance or something done before another's hand does it. Hyphenated from 18c.; one word from 19c.
