Rif Gittin 43a {82a}

43a

{Gittin 82a}
BEGIN PEREK NINE
Mishna:

המגרש את אשתו ואמר לה הרי את מותרת לכל אדם אלא לפלוני
ר"א מתיר
וחכמים אוסרים
כיצד יעשה יטלנו ממנה ויחזור ויתננו לה ויאמר לה הרי את מותרת לכל אדם
ואם כתבו לתוכו אע"פ שחזר ומחקו פסול

IF A MAN ON DIVORCING HIS WIFE SAYS TO HER, YOU ARE HEREBY FREE TO MARRY ANY MAN BUT SO-AND-SO, RABBI ELIEZER PERMITS HER {TO REMARRY} BUT THE RABBIS FORBID HER. WHAT MUST HE DO? HE MUST TAKE IT BACK FROM HER AND GIVE IT TO HER AGAIN SAYING, YOU ARE HEREBY FREE TO MARRY ANY MAN. IF HE WROTE IT BUT THE RABBIS FORBID HER. WHAT MUST HE DO? HE MUST TAKE IT BACK FROM HER AND GIVE IT TO HER AGAIN SAYING, YOU ARE HEREBY FREE TO MARRY ANY MAN.
IF HE WROTE IT IN THE GET, EVEN THOUGH HE SUBSEQUENTLY ERASED IT, IT IS INVALID.

Gemara:

איבעיא להו האי אלא חוץ הוא או ע"מ הוא
חוץ הוא ובחוץ הוא דפליגי רבנן עליה דר"א דהא שייר לה בגט אבל בע"מ מודו ליה מידו דהוה אכל תנאי דעלמא

It was a question to them: This "except" {to Ploni}, it is to the exclusion {such that the divorce is not effective to permit her to Ploni}, or on the condition {that if she marries Ploni, this was not a get at all}?
If it is "to the exclusion of," and it is about "to the exclusion of" that the Sages argue upon Rabbi Eliezer, for he leaves to her {some aspect of non-divorce} in the get. But by "on condition of," they admit to him, for it just as any other general condition.