Rabbi Evyatar in Israel sent a message to Rav Ḥisda in Babylon, telling him that giṭṭin sent “from Bavel to Israel” do not require the messenger to attest that the geṭ was written and signed in his presence. The Gemara’s first suggestion in explaining this ruling is that Rabbi Evyatar must agree with Rabbah (see daf 3) and believe that the potential problem is that the court where the geṭ was written may not know how to write the geṭ properly. Since the Babylonian Jewish community was knowledgeable, this would not be a problem. In response, the Gemara points out that even Rabbah accepts Rava’s concern that in places far away from one another we fear that no witnesses will be available to verify the signatures on the geṭ (see daf 4). Finally, the Gemara explains this is not an issue because of the large number of people who travel from Babylonia to Eretz Yisrael.
From many sources it appears that during the early part of the period of the amoraim there was a large movement of people who moved from Babylonia to Israel. Most of Rabbi Yohanan’s students in Israel were originally from Babylon, and we find many other Babylonian students and sages in Israel, as well. We cannot be certain of what the impetus was for this migration, although it is likely that the growth and development of the yeshiva headed by Rabbi Yohanan – the acknowledged leader among the sages at that time – played some role in it. Although there was no violence against Jews in Israel during this period, it was, nevertheless, a period of high taxes and political unrest throughout the Roman Empire. Therefore, it was difficult for people who moved there from Babylonia to find means of support for themselves, and even more difficult to support their families left behind in Babylonia. Since the tradition in Babylonia – as opposed to Israel – was for men to get married at a young age and continue to learn Torah afterwards, those students who chose to move to Israel were perceived by many sages as having abandoned their wives and children, a decision for which those sages criticized them.