Some Color on Rav Matna I
My article for this past Shabbos in the Jewish Link, all about Rav Matna, who made the derasha on the word יהיה to deduce that an otherwise unspecified period of nezirut is 30 days. He likely didn’t innovate that gematria. Given context, he is Rav Matna I, the student of Shmuel.
While one source describes him as Rabbi Yochanan’s surviving son, this seems unlikely. Rav Matna I is also the Sage who comes up with the famous Pentatuechal allusions to Moshe (prior to Moshe’s birth), Esther, Mordechai and Haman. And the famous story of mayim shalanu, our water.