Friedrich Kluge2506835An Etymological Dictionary of the German Language, E — es1891John Francis Davis
es, pron., ‘it,’ from MidHG. ëȥ, n. sing., and its gen. ës, OHG. ëȥ (gen. ës); formed from the Aryan pronom. stem of the 3rd pers. (i-) mentioned under er. See ihn.