Where does “изјавити” come from?

изјавити (Serbo-Croatian) comes from Serbo-Croatian из, from Proto-Slavic jьz, from Proto-Balto-Slavic iź, from Proto-Indo-European h₁eǵʰs — out.

Ancestry of “изјавити”, step by step

Step	Language	Word	Meaning
1	Serbo-Croatian	из	from, out of; for, because of, out of; with,...
2	Proto-Slavic	jьz	from, out of
3	Proto-Balto-Slavic	iź	—
4	Proto-Indo-European	h₁eǵʰs	out

изјавити — Etymology, Origin & Word History | Etymology Explorer