Where does “ـٔ” come from?

ـٔ (Classical Persian) comes from Middle Persian Y, from English hyah, from Proto-Indo-Aryan Hyás, from Indo-Iranian *Hyás, from Proto-Indo-European Hyós — who, which; already.

Ancestry of “ـٔ”, step by step

StepLanguageWordMeaning
1Middle PersianY—
2Englishhyaha call, often to horses, livestock, or cattle, to...
3Proto-Indo-AryanHyás—
4Indo-Iranian*Hyás—
5Proto-Indo-EuropeanHyóswho, which; already
Every word from Proto-Indo-European Hyós →Every word from Indo-Iranian *Hyás →Every word from Proto-Indo-Aryan Hyás →