Where does “wyście” come from?

wyście (Polish) comes from Polish wy, from Old Polish wy, from Proto-Slavic vy, from Proto-Indo-European wōs.

Ancestry of “wyście”, step by step

StepLanguageWordMeaning
1Polishwyyou
2Old Polishwyplural second person pronoun; you
3Proto-Slavicvyyou, ye; you
4Proto-Indo-Europeanwōs—
Every word from Proto-Indo-European wōs →Every word from Proto-Slavic vy →Every word from Old Polish wy →