IE "fist" (Germanic+Slavic+Baltic?)

Hello everyone!

Could somebody, please, help me with the etymology of "fist"?

I'm somewhat puzzled by the fact that in some dictionaries, the Germanic and Slavic forms are linked to the Baltic ones. How secure is the etymology and are we not dealing with a loan (e.g. from a source close to Semitic) rather than native IE etymon? Thank you for any advice in advance!

Best,

P.