Premise: Eli ben Yehudah ha Nazir ben Zechariah, Arabic Abu Kathir Yahya al Katib ("Father of Kathir, Yahya the Scribe" fl.Tiberias, 910s) was a grammarian and philologist of the Hebrew, Arabic and Aramaic languages. He may have been among the teachers in Tiberias of Saadia.
Hypothesis:  Eli ben Yehudah ha Nazir ben Zechariah was a philologist and may have been among the teachers in Tiberias of Saadia