Tosefta sobre Demai 6:13

How [else] is this done? We do not take terumah from produce from the Land [of Israel] on behalf of produce from outside the Land [of Israel], we do not take terumah from produce from the Land of Israel on behalf of produce from Syria (see Dem. 6:11), and not from produce from Syria on behalf of produce from the Land of Israel. A Jew that bought a field in Syria, behold, he is like someone who buys [a field] in the outskirts of Jerusalem (see Challah 4:11, "בְּפַרְוָר" = outskirts, not "בפרוזדור" = vestibule, see Lieberman here), and [therefore he must] take terumah and tithes on it.

Rabbi Yosei ben HaMeshullam testified in the name of his brother Rabbi Nathan, who said in the name of Rabbi Eliezer ben Hasma (alt., "R. Eliezer Hasma"), "If one rented from a Gentile a field which had formerly belonged to his fathers [for a share in the produce], he gives him (i.e., the Gentile his portion) as they are (i.e., without separating tithes or Terumah)." (But see Dem. 6:2, Kulp tr.).

They [a chaver and an am ha'aretz] inherited from their father who was a chaver, [the chaver] has the right to say, "You take the wheat that is in such-and-such a place and I [will take] the wheat that is in such-and-such [other] place" [or] "[You take the] wine in such-and-such a place and I [will take the] wine in such-and-such other place," even though they said, "a chaver that dies and leaves sons who are chaverim and amei ha'aretz, the amei ha'aretz does not pass on Tahorot to the amei ha'aretz, but only to the chaverim." If he leaves second-tithe produce, [the chaver] has no right to say to [the am ha'aretz], "You take the wheat and I will take the barley," [or] "you the wine and I the oil" (cf. Dem. 6:9), but he [may] say to him, "You take money from [the sale of the] wheat, and I will take the money from [the sale of] the barley," [or] "you the money from the wine and I the money from the oil."