behest

The story

1. Proto-Germanic · derived from*haisiz
2. Proto-West Germanic · derived from*bihaisi
3. Old English · inherited frombehǣs“vow, promise”
4. Middle English · inherited frombiheste
5. English todaybehest

From Middle English biheste, from Old English behǣs (“vow, promise”), from Proto-West Germanic *bihaisi, from *bi- (“be-”) + *haisi (“command”), from Proto-Germanic *haisiz, from *haitaną (“to command”). Final -t by analogy with other similar words in -t. Related to Old English behātan (“to command, promise”), Middle Low German beheit, behēt (“a promise”). Compare also hest (“command”), hight.

First known use, by meaning

• from 12th c. A command, bidding; sometimes also, an authoritative request; now usually in the phrase at the behest of and at one's behest.