Where does “mikäkin” come from?

mikäkin (Finnish) comes from Finnish mikä, from Finnish Mikael, from Latin Michāēl, from Latin Michahel, from Greek Μιχαήλ, from Ancient Greek Μιχαήλ, from Hebrew מיכאל, from Hebrew אֵל.

mikäkin (Finnish): which used always in connection with another interrogative pronoun