Tosefta zu Bamidbar 19:19

[With respect to] a storehouse that Jew[s] and Gentiles deposit [their produce] inside, if the majority are Gentiles, it is [considered] certainly untithed, and if the majority are Jew[s], it is [considered] Demai. If it is half and half, it is [considered] certainly untithed, the words of Rabbi Meir. And the Sages say, even if everyone [who deposited produce were] Gentiles, and a single Jew deposits inside it, [all of the produce is considered] Demai. Rabbi Yosei said, in what context does this apply? With respect to a storehouse owned by a private citizen, but with respect to a storehouse owned by kings, we follow after [the rule of] the majority. Rabbi Yehudah said, in what context does this apply? With respect to a storehouse [belonging to] Jew[s] and Gentiles, but [with respect to] a storehouse [belonging to] Jew[s] and Samaritans, we follow after [the rule of] the majority. They said to him, [how can you say that] after you [previously] rendered the ruling on us that, "The storehouses of Yavneh [dating] from before the [Jewish-Roman] War were Demai, [even though] the majority were Samaritans, but a storehouse to which [produce] is taken from outside the Land of Israel into the Land of Israel, such as storehouses of Danab, they are liable [in the laws of Demai], according to the proportion." Rabbi Yehoshua son of Kevisai, said, every day I was reading this passage (Num. 19:19), "The clean person shall sprinkle it upon the unclean person," and I did not understand it, but only in the storehouse of Yavneh [did I come to understand it], and from the storehouse of Yavneh I learned that one pure [person] can sprinkle even onto a hundred impure [people and render them clean].