Gittin 2 - A messenger of divorce
To divorce his wife, the husband must write for her a document of divorce, called Get, and give it to her. He can even appoint a messenger to bring and give her the Get.
In case he appoints a messenger, and this messenger comes from overseas, there is an additional requirement for him. He has to verify that he himself saw the Get being written by the scribe and signed by the witnesses. Why this requirement? - People outside of Israel were not expert in the laws of divorces, and they might have missed a very important condition: that the Get is written for the specific woman whom the husband wants to divorce. It cannot therefore be written in advance, nor can a printed form be used. So if the scribe or the witnesses miss this, the Get would be invalid, even though the document would look OK, and this could create a problem later on. This is the opinion of Rabbah.
However, Rabbah's student, Rava, said that the reason is different: people who live overseas stay overseas, and should the husband protest the Get and claim that it is forged, it would be hard to find these witnesses and make them testify in court. Thus, the husband could nullify the Get, and this could create a problem as well.
What does it matter what the reason is, if the messenger has to say these words, "written and signed in front of me" anyway? - For example, if two messengers came. The reason of Rava - that they can't find two witnesses would not apply any longer, so they don't need to make the statement. But the reason of Rabbah - that they may not written the document specifically for her - would still be true, and accordingly they would have to talk about how it was written and signed.
Art: Still Life with Documents by John Turing