“Be it ever so humble ”

Merriam-webster- so be it(let it be)

On your head be it

• The phrase “on your own head be it” is common and has the well-attested meaning of roughly “I think this is a really terrible idea but you’re the one who will suffer the consequences so do what you like.”
• The earliest quote in the OED for this expression is from 1743:
• When they promise it [sc. protection], they put their hands up to their turbants, as much as to say, Be it on their heads. A description of the East, and some other countries
• However, I think I found an earlier example from 1711:
• If you dissemble, be it on your head The maids tragedy
• The expression "on your head", however, is much older than the longer expression (and apparently comes from the Latin expression in caput eius meaning "onto his/her head"). Since Old English, it was used in the sense "Of a misfortune, curse, blessing, etc.: directed towards a person; so as to affect a person; on a person." (OED):

• In the sense "So as to be the responsibility of a person; weighing on a person", the earliest attestation the OED has is from a1425:
• The blood of hym schal be on his heed [a1382 E.V. into his hed, L. in caput eius], that goith out at the dore of thin hows. John Wycliffe Bible
• It appears it is from the Bible:
• “On your own head be it”
• Source: This phrase has its origins in Psalm 7:16 and Acts 18:6 of the King James Version of the Bible.
• Meaning: the ultimate responsibility is yours
• and according to the AHD it dates back to the 14th century:
• On one's head:
• Also, on one's own head . As one's responsibility or fault, as in If the police catch you speeding it's on your own head . This idiom, dating from the 1300s, conjures up the image of blame or guilt falling on someone's head.