What is the variant bā character for 巴掌?
「」 fulfils the statement 《說文》：‘��，��擊也。’ (check the Shuowen entry on zdic), and also everything else.


  耳巴，或作 “耳「」”。民國十八年《榮縣志·禮俗》：“《說文》： ‘獸足謂之番。’ 附袁切。古無輕唇音，番讀如班，今音如板， 手掌謂手番， 足掌曰足番，雙聲轉「」。《說文》： ‘「」，「」（批）擊也。’ 今「」掌、耳「」，北人强以刮字當之， 非也。”


Note,


Zdict lists「」with the third tone, not the first tone (bā). I can't confirm with an external resource about this tone.
北人强以刮字當之 is saying that there are multiple words for「耳巴」, like「耳光」,「耳摑」,「耳刮子」, etc.