We begin our study of Maseches Gittin, Chapter 1, Mishnah 1.
The Mishnah opens: "HaMevi get mimedinas hayam tzarich sheyomar b'fanai nichtav uv'fanai nechtam" - an agent who is sent to bring a get to a woman so that she may be divorced with it, and who brings it from overseas, from outside Eretz Yisrael, is required to declare at the time he hands over the get that this get was written in his presence and that its witnesses signed it in his presence.
What is the reason for this declaration? The Amoraim of the Gemara disagree, and we will explain the Mishnah according to both opinions:
Rabbah - "lefi she'ein beki'in lishmah": People overseas are not expert in the law that a get must be written and signed for the sake of this particular man and this particular woman, and without that the get is invalid. The agent's declaration establishes that the get was written properly, lishmah.
Rava - "lefi she'ein edim metzuyin lekaymah": If the husband should protest and claim that the get is a forgery, we must be able to verify the signatures of the witnesses. Because of the distance, there are no people available who recognize the signatures and can testify that they are valid. For this reason the Sages permitted, as an exception to the rule, relying on the testimony of the agent alone, even though he is only a single witness, and his declaration validates the get.
How far out does a place count as "overseas":
"Rabban Gamliel omer: af hamevi min haRekem umin haChager" - even one who brings a get from these two cities, which lie close to Eretz Yisrael just beyond its southeastern border, must say "b'fanai nichtav uv'fanai nechtam." According to Rabbah, even though they are nearby, their residents are still not expert in the law of lishmah; and according to Rava, few people travel from there to Eretz Yisrael, and therefore once again no witnesses will be found to verify the signatures.
"Rabbi Eliezer omer: afilu miKfar Ludim l'Lud" - even this small village adjacent to Lud, the two being right next to each other and even within the Shabbos boundary, within two thousand amos. In reality, the residents of such a nearby place are expert in the law of lishmah, and people are also available who can verify the signatures. Rather, Rabbi Eliezer holds that no distinctions are drawn regarding overseas - one does not differentiate between one place outside Eretz Yisrael and another, and therefore the Sages spoke in sweeping terms that one must say "b'fanai nichtav uv'fanai nechtam."
The opinion of the Sages: "VaChachamim omrim: eino tzarich sheyomar b'fanai nichtav uv'fanai nechtam, ela hamevi mimedinas hayam v'hamolich" - that is, the obligation applies both to one who brings a get from overseas to Eretz Yisrael and to one who takes a get from Eretz Yisrael to overseas.
According to Rabbah, the Sages disagree with the first Tanna. The first Tanna holds that only one who brings a get from outside the Land must say "b'fanai nichtav uv'fanai nechtam," but one who brings a get from Eretz Yisrael is exempt, since in Eretz Yisrael people are expert in the law of lishmah. The Sages then come and say that they enacted a decree: even though in Eretz Yisrael people are expert in lishmah, so that the reason does not apply, nevertheless, because of the enactment stated regarding a get coming from outside the Land, they enacted that one who takes a get from Eretz Yisrael to outside the Land must also say "b'fanai nichtav uv'fanai nechtam."
According to Rava, the Sages are not disagreeing with the first Tanna but explaining his words: since the problem is the absence of witnesses to verify the signatures on the get because of the distance, this problem exists equally whether one comes from outside the Land to Eretz Yisrael or goes from Eretz Yisrael to outside the Land, and in both cases the declaration is required.
From one country to another within the overseas lands: The Mishnah continues - "Hamevi mimedinah limedinah bimedinas hayam tzarich sheyomar b'fanai nichtav uv'fanai nechtam". According to Rabbah, this is the issue of lishmah, which exists in every place overseas; and according to Rava, since the get passes from one country to another, there are no witnesses available in one country who can verify the signatures of witnesses from another country.
"Rabban Shimon ben Gamliel omer: afilu meHegmonya l'Hegmonya" - even within a single city, like East Berlin and West Berlin, where one cannot cross from one section to the other because a governmental barrier separates the two, there too one must say "b'fanai nichtav uv'fanai nechtam." The Gemara explains that the Mishnah refers to such a city within Eretz Yisrael, and the problem is that there is no way to verify the witnesses since people do not cross from one side to the other. It emerges that even Rabbah agrees with Rava's reason of verifying the witnesses; in his view, however, there is in addition the problem of lishmah in a get coming from outside the Land.
In summary: We learned the law of one who brings a get from overseas, who is required to declare "b'fanai nichtav uv'fanai nechtam," and the two reasons for the enactment - "ein beki'in lishmah" according to Rabbah, and "ein edim metzuyin lekaymah" according to Rava. We examined the dispute among the Tannaim as to how far out a place counts as overseas (Rekem and Chager, Kfar Ludim and Lud), the opinion of the Sages that obligates even one who takes a get from Eretz Yisrael overseas, and the law of one who brings a get from one country to another and from one hegmonya to another - from which it emerges that even Rabbah agrees with the reason of verifying the witnesses.