Where does “обьщина” come from?

обьщина (Old East Slavic) comes from Old Church Slavonic обьщина, from Proto-Slavic obьťina, from Proto-Slavic obьťь — common.

Ancestry of “обьщина”, step by step

StepLanguageWordMeaning
1Old Church Slavonicобьщинаcommon thing, something in common
2Proto-Slavicobьťinacommunity
3Proto-Slavicobьťьcommon
Every word from Proto-Slavic obьťь →Every word from Proto-Slavic obьťina →Every word from Old Church Slavonic обьщина →