I am having difficulty in understanding the Gemorrah on Daf 58a, about half way done.
Just after the "Omar Mar...", the Gemorrah asks according to R'Eliezer - "Eimeh Eishes Oviv ?", to which the Gemorrah answers - "Hiynu Be'ishto Ve'lo Be'eshes Chavero". The Gemorrah seems to be saying that Eshes Oviv is already included in Eishes Chavero (Eishes Chavero having been learnt out from "Be'ishto" above) and therefore Ossur according to R'Eliezer. However, from the Beraissa at the top of the page - which the Gemorrah has just explained is R'Meir ACCORDING TO R'Eliezer - we see that Eishes Oviv is Mutar ! ("Le'ituye Eishes Oviv"). It is true that that Beraissa is talking about a "semi-Ger semi-Ben Noach", but, as Rashi explained on the top of the page, the Rabanan made a Gezeira that anything that was Ossur to him while he was a Ben Noach will be Ossur to this "semi-Ger semi-Ben Noach".
I thought to answer by saying that R'Meir is only going according to R'Eliezer in certain details of the Beraissa, but doesn't hold like him in every issue. Is this right ?
I think I may be missing a simple point here !
Thank you in advance for any answer.
Shlomo Steinhart, Ramat Bet Shemesh, Israel.
Rebbi Eliezer does not prohibit Eshes Aviv to a Ben No'ach *after his father dies* (or after his father divorces his wife). That is why we identify the Beraisa of Rebbi Meir with the opinion of Rebbi Eliezer. The Gemara with which you are having difficulty is asking why Rebbi Eliezer does not learn that the word "Aviv" refers to his father's wife *while the father is alive*, who is Asur. The Gemara answers that such an Eshes Aviv would be Asur because of Eshes Ish.
The Gemara then continues to ask, why didn't Rebbi Eliezer explain that the word "Aviv" in the Pasuk refers to Eshes Aviv *after the father dies* (which is indeed Mutar according to Rebbi Eliezer). The Gemara answers that the verse implies that it is referring to a blood relative and not a marital relative.