Where does “ѩзꙑкъ” come from?
ѩзꙑкъ (Old Church Slavonic) comes from Proto-Slavic ęzykъ, from Proto-Balto-Slavic inźūˀ-kas, from Proto-Balto-Slavic *inźūˀs, from Proto-Balto-Slavic *dinźūˀs, from Proto-Indo-European dn̥ǵʰwéh₂s — tongue.
ѩзꙑкъ (Old Church Slavonic): language; tongue; people
Ancestry of “ѩзꙑкъ”, step by step