Gemara

(Abaye): A Yad (an abbreviated expression) that is not clear (how to complete it) is valid (it is as if he said the full expression);

(Rava): Ambiguous Yados are invalid.

Suggestion: Abaye and Rava argue like Chachamim and R. Yehudah:

(Mishnah): The essential part of a Get is 'you are permitted to every man';

R. Yehudah says, it is 'v'Dein (and this Get) will be for you, Minai (from me), a Sefer of cutting...'

Abaye holds like Chachamim, and Rava holds like R. Yehudah!

Rejection #1: Even R. Yehudah could agree with Abaye. R. Yehudah requires unambiguous Yados only for Get, which requires Kerisus (a total severance).

Rejection #2: Even Chachamim could agree with Rava. Chachamim allow ambiguous Yados only for Get, for one cannot divorce another man's wife (so it is clear that he divorces her), but not in other cases.

Gitin 85b - Question: What do R. Yehudah and Chachamim argue about?

Answer: Chachamim hold that an ambiguous Yad is valid. Even though he did not write 'v'Dein... ', it is clear that he divorces her through the Get'

R. Yehudah holds that an ambiguous Yad is not a Yad. If he does not write 'v'Dein...', perhaps he divorces her verbally, and the Get is just for a proof.

Question: Must one write 'v'Dein...'?

Answer: Rava enacted that a Get should say 'Ploni...cut off Plonis...from this day and forever.' He did not mention ''v'Dein...'!

Rejection: He did not mention other things that must be in the Get. Likewise, he did not mention 'v'Dein'.

Kidushin 5b (Shmuel): If a man gave a woman money or something worth money, and said 'behold, you are Mekudeshes' ... she is Mekudeshes. If he said 'I am your husband'... she is not Mekudeshes;

Similarly regarding divorce, if one gave her a Get and said 'behold, you are sent'... she is divorced. If he said 'I am not your husband'... she is not even doubtfully divorced.

Question (Rav Papa): Here, Shmuel holds that ambiguous Yados are valid (he did not specify that she is Mekudeshes to him). Elsewhere, he taught differently!

Answer (Abaye): The case is, he said '(you are Mekudeshes) Li (to me).'

Rishonim

The Rif and Rosh (Gitin 45a and 9:4): bring the question about 'v'Dein', the answer and the rejection.

Ran (DH Iboi): Our Sugya in Gitin is contrary to the Sugya there in Nedarim. There, we suggested that R. Yehudah and Chachamim argue about ambiguous Yados, like Rava and Abaye. We reject this. Perhaps R. Yehudah normally allows such Yados, but not for a Get, which needs Kerisos. Alternatively, perhaps Chachamim allow such a Yad only for Get, for clearly a man does not divorce another man's wife. They argue about whether or not one must say 'Minai' (the Get is from me). Here, we say that they argue about 'v'Dein', and we accept the premise that they argue about ambiguous Yados! This is not difficult. Indeed, each Sugya discusses a different matter!

Ran (45b DH v'Ika): Some say that since Chachamim do not require 'Minai', the Halachah follows them, even though the Halachah follows Rava that ambiguous Yados are invalid. This is because we said that even Chachamim could hold like Rava. However, we require 'v'Dein'. Our Sugya did not settle this, so we must be stringent. Perhaps R. Yehudah's reasoning regarding 'v'Dein' is better than his reasoning regarding 'Minai'. Others say that Chachamim do not require v'Dein or Minai because they allow ambiguous Yados. We require 'v'Dein' because the Halachah might follow Rava and R. Yehudah, that ambiguous Yados are invalid, therefore we require also Minai.

Rif (Kidushin 2a and Rosh 1:2): Shmuel taught that if a man gave a woman money and said 'behold, you are Mekudeshes Li', she is Mekudeshes. Similarly, if one gave a Get and said 'behold, you are sent', she is divorced.

Ran (DH Omar): The Halachah follows Rava, that ambiguous Yados are invalid. It seems that also regarding a Get, he must say 'Minai'. The Rif mentions 'Li' regarding Kidushin, but not 'Minai' regarding divorce. Some say that because it says 'Minai' in the Get, the husband need not say it. I disagree. The Rif did not say 'he gave a Get and said...' It seems that the Rif discusses what is written in the Get. The Rambam (1:4) discusses Gitin in which are written the expressions Shmuel taught about. The Rif agrees. He relies on the Sugya in Nedarim. It answers for Rava that Chachamim do not require Minai in a Get, for one cannot divorce another man's wife, but other ambiguous Yados are invalid. In Gitin, we did not settle whether or not we need v'Dein. The Rif requires 'v'Dein', like Rava and R. Yehudah, for one might have thought that he divorces verbally. Regarding Minai, we follow Chachamim, since even Rava could agree. Also the Rambam omitted Minai for this reason.

Rambam (Hilchos Gerushin 1:4): The essence of a Get is 'Behold, you are permitted to every man.

Question: It seems that here, the Rambam rules like Chachamim. Below (4:12), he rules like R. Yehudah, who requires 'v'Dein'!

Answer #1 (Ran Gitin 45b DH v'Ika): The Rambam rules totally like Chachamim. Even though in Perek 4 he writes 'v'Dein', this does not mean that it is essential. He holds that the question was not settled here, but it was settled in Nedarim that Rava holds even like Chachamim. This is not clear.

Rebuttal (Lechem Mishneh): If so, what was the Gemara's attempted proof from Rava, who enacted a text of Gitin without 'v'Dein'? Everyone requires this l'Chatchilah!

Answer #2 (Lechem Mishneh): The Rambam explains that we asked whether or not Chachamim require v'Dein l'Chatchilah. The question was not settled, therefore the Rambam requires it l'Chatchilah. Even though it is a Safek mid'Rabanan, since R. Yehudah requires it even b'Di'eved, we are stringent l'Chatchilah. A support for this is that the Gemara did not ask whether or not the Halachah follows R. Yehudah, rather, whether or not we need v'Dein. However, the Magid Mishneh (4:12) says that the Ramban and Rashba rule like R. Yehudah. This connotes that the Rambam agrees. If so, why did he omit v'Dein here?

Answer #3 (Lechem Mishneh 4:12): Perush ha'Mishnayos says that even though the essence of a Get is 'Behold, you are permitted to every man', one must write v'Dein; the Halachah follows R. Yehudah. This connotes that R. Yehudah requires v'Dein only mid'Rabanan. Surely other things that R. Yehudah mentions, e.g. 'a Sefer of cutting', are mid'Rabanan. In Perek 1, the Rambam wrote what is required mid'Oraisa.

Rambam (4:12): The text of a Get is... 'v'Dein will be for you, from me, a Sefer of cutting...'

Rambam (13): One must not write v'Dein with a Yud, lest it be read 'v'Din', i.e. the man has a court case with his wife.

Poskim

Shulchan Aruch (EH 126:9): One should write 'v'Dein' without a Yud.

Beis Yosef (DH v'Garsinan): The Rif and Rosh bring the Gemara's discussion about v'Dein. This implies that they require it, for the question was not resolved, so we are unsure and must write it due to Safek.

Beis Yosef (DH v'Chosav and DH v'Rabbeinu): The Ran says that we require v'Dein like R. Yehudah, but not Minai. The Tur understands that the Rosh requires both, since he brought the Sugya without specifying. This implies that if we follow R. Yehudah, we follow everything he said in the Mishnah.

Pischei Teshuvah (17): Get Pashut says that according to the Rambam, if 'v'Dein' was written with a Yud, the Get is Pasul, for it is read 'v'Din', and it is not clear that he divorces through the Get.

Rema (Seder ha'Get, 154:101): The text of the Get we usually use in these lands, especially in this city, is '...v'Dein Di Yehavi Lechi Minai...'