How come (for nusach Ashkenaz) Shochen Ad spells out Isaac & Rivka on Yom Kippur, but only Isaac is spelled on regular shabbos? For Sephardim and nusach Sephard, it always spells out both names.
Furthermore, the ArtScroll commentary for the shabbos Shochen Ad says that Isaac is probably the name of the author, ignoring the potential Rivka connection. Whats up with that?
