Parallel to the laws taught in the Mishnah on yesterday’s daf (=page), the Gemara quotes a baraita that teaches a similar halakhah regarding kutim. Thus, there were places in Israel where Jews sold behemot dakot – sheep and goats – to kutim, while in other places they did not.
The term kutim refers to those people who were brought to Israel in a population exchange during first Temple times, when the kings of Assyria exiled the Northern kingdom and replaced them with other nations – not all of whom were truly kutim. They settled in the area around the city of Shomron (Samaria), which is why they are also called Shomronim or Samaritans.
In II, or Kings (chapter 17) the navi describes how these nations accepted upon themselves some of the Jewish laws and customs out of fear after they were attacked and killed by lions – which is why they are often called gere arayot – converts because of lions. At the same time they did not renounce their own gods and religious traditions.
At the beginning of the second Temple period, when Jews of the Diaspora began returning to the land of Israel, the relations between the Jews and the Shomronim became tense, with the Shomronim trying to bring down the efforts to rebuild the wall surrounding the city of Jerusalem and the bet ha-mikdash. At the same time, there were Jewish families – including families of kohanim – who intermarried with the Shomronim and assimilated with them.
During some periods, the relations between the two groups reached levels of overt warfare; Yohanan Hyrcanus even attacked and destroyed their temple on Mount Gerizim. During other periods, however, there was cooperation between the groups – during the bar Kokhba rebellion, for example.
Generally speaking, the Sages believed that the kutim were scrupulous in keeping those mitzvot that they accepted, and our Gemara argues that kutim were not known to engage in acts of bestiality. Nevertheless, places where such behavior was commonplace among the local non-Jews the tradition was to avoid selling animals to kutim lest they sell them to the pagan idol worshipers.