Tosefta zu Demai 2:10

Rice in its place (i.e., wherever it grows) is permitted [without tithing] in the harbor/suburb area (see Jastrow re חולת אנטכיא, following the GR"A) of Antioch. Rabbi Eliezer son of Rabbi Yosei says, "Rice in the harbor/suburb area of Antioch is permitted until Borek (=בורק, following the GR"A). (Cf. Dem. 2:1.)

An am ha'aretz that brings utensils for his purification, a chaver (i.e., one who is strict in matters of purity, see Dem. 2:3) may buy them from him for [purposes of] the purification rite as well as for [purposes of separating and storing] his Terumah. [If] he brought [utensils] for his Terumah, a chaver may not buy them from him neither for the purification rite nor for his Terumah. A chaver who said to an am ha'aretz, "Bring utensils for [my] purification," the chaver may buy them from him for his purification and for his Terumah. [If he said, "Bring utensils for] my purification," the chaver may not buy them from him, neither for his purification nor for his Terumah. [If he said,] "Bring [utensils] for my purification and for my Terumah of purification," the chaver may buy them from him, whether for himself or for someone else, as long as he did not try to circumvent the law [by going to an am ha'aretz]. And if he did try to circumvent the law, behold, they (i.e., the utensils and the items with which they came in contact) are impure. An am ha'aretz that said, "I brought these utensils for my purification, and I decided to use them for my Terumah," since they had been left alone with an am ha'aretz for a period of time [after he changed his mind and redesignated them], behold, they are impure.

[The Mishnah, Pes. 3:8, says that one who leaves Jerusalem and remembers that he is carrying consecrated meat may burn it where he stands if he has passed Mount Scopus, but otherwise he must return to the Temple and burn it there.] What is [Mount] Scopus? [It is the place from where] one sees [all of Jerusalem] and there is nothing that obstructs [his view]. You say, one who is on his way to slaughter the Passover offering, or to circumcise his son, or to eat at a betrothal feast in his father-in-law's house, and he remembers that he has chametz inside his house, if he has enough time to return, he returns [to his house and removes the chametz], and if not, he does not return [but rather he annuls it in his heart]. Rabbi Shimon ben Elazar says, any feast [hosted by an am ha'aretz] that is not in furtherance of a mitzvah, a chaver is not permitted to eat from it (see Dem. 2:3). If he passed [Mount] Scopus, he burns it (i.e., the consecrated meat) where he stands, and if not, he returns and burns it in front of the Temple with wood from the [Altar] pile. In other words, they only said that he need not return in order to make it easy on him. How much [consecrated meat or chametz triggers the requirement that] they return? Ben Beteira says, [if] it has at least the equivalent of two eggs'-bulk, but we did not find anyone who agreed with him (see Pes. 50a:2). [If] he wanted to burn it in front of the Temple with his own wood, or on its roof with wood from the [Altar] pile (see Zeb. 107b:14), we do not listen to him.

[If a man] was trustworthy but his wife was not trustworthy, we may purchase [produce] from him but we may not be guests at his house, and [that is so] even though the [Sages] said, behold, he is like one who dwells with a snake in a wicker basket (i.e., his wife will control what is served and he will not interfere). [If] his wife is trustworthy but he is not trustworthy, we may be guests and his house, but we may not purchase [produce] from them. [If] he is trustworthy and one of his sons is trustworthy, or one of his (male) servants is trustworthy [see Lieberman, ואחד מעבדיו נאמן], or one of his female servants is trustworthy, we purchase [produce] and we eat [their produce at their homes] on their word [that their produce is tithed] and we prepare food for them. [But] during Shevi'it (the seventh year of the agricultural cycle, when fields must lie fallow) as as to Taharot (foods requiring preparation in a state of ritual purity), we are not allowed to do that (i.e., trust them at their word). [Note: Unlike a chaver, one who is "only" trustworthy is only trusted in regards to tithing, but not as to whether produce was grown during Shevi'it, or in matters of Taharot, see, e.g., Dem. 2:2, Dem. 2:3, Dem. 3:4.]

[If a man] was trustworthy but his wife was not trustworthy, we may purchase [produce] from him but we may not be guests at his house, and [that is so] even though the [Sages] said, behold, he is like one who dwells with a snake in a wicker basket (i.e., his wife will control what is served and he will not interfere). [If] his wife is trustworthy but he is not trustworthy, we may be guests and his house, but we may not purchase [produce] from them. [If] he is trustworthy and one of his sons is trustworthy, or one of his (male) servants is trustworthy [see Lieberman, ואחד מעבדיו נאמן], or one of his female servants is trustworthy, we purchase [produce] and we eat [their produce at their homes] on their word [that their produce is tithed] and we prepare food for them. [But] during Shevi'it (the seventh year of the agricultural cycle, when fields must lie fallow) as as to Taharot (foods requiring preparation in a state of ritual purity), we are not allowed to do that (i.e., trust them at their word). [Note: Unlike a chaver, one who is "only" trustworthy is only trusted in regards to tithing, but not as to whether produce was grown during Shevi'it, or in matters of Taharot, see, e.g., Dem. 2:2, Dem. 2:3, Dem. 3:4.]

Certainly untithed produce that was tithed (lit., "fixed") as Demai (i.e., the owner thought it was Demai so he only took out Terumah of tithes (Dem. 2:4), per Minchat Yitzchak), or Demai that was tithed as certainly untithed produce (and thus took Terumah from the whole), he has done nothing (i.e., the tithe is not effective and the status remains as it was), the words of Rabbi Ya'akov (alt., "Rabbi Meir," per MS Erfurt). Rabbi Yosei says, [as to] certainly untithed produce that was tithed as Demai, nothing has happened, [but as to] Demai that was tithed as certainly untithed produce, its tithes are [considered valid] tithes, but its Terumah is not [valid] Terumah, as one may not separate Terumah after Terumah [has already been taken]. [Note: Since even an am ha'aretz is presumed to have separated Terumah, separating Terumah here would result in two Terumahs taken from the same produce (see Minchat Yitzchak here).]

As for olives, [their status for purposes of Demai] is determined from the time they are made into oil (משיעסום not משיחסום per GR"A), [depending on whether they are pressed] in the larger olive press or in the smaller olive press (see Sheviit 8:6 (בד/בודידה)), the words of Rabbi Meir. But the Sages say, neither [all] larger olive presses nor [all] smaller olive presses are comparable, either in the towns or in the provinces. The majority in the towns is not [like] the majority in the provinces; what is permitted [to buy, sell, or consume without tithing] in the towns is prohibited in the provinces (i.e., the majority of certain species of produce in the towns is generally imported and not subject to tithes, while the majority of that same species sold in the provinces is grown in the Land of Israel and thus treated as Demai, see Y. Dem. II.1.8, and Mishneh Torah, Tithes 13:12)). [Conversely,] the majority in the provinces is not like the majority in the towns; what is permitted in the provinces is prohibited in the towns. The majority in the mountains is not like the majority in the valleys; what is permitted in the mountains is prohibited in the valleys. [Conversely,] the majority in the valleys is not like the majority in the mountains; what is permitted in the valleys may be prohibited in the mountains. The majority [of produce sold by] the store-owner is not like the majority [sold by] the homeowner; what is permitted [to sell without tithing] for the storeowner is forbidden for the homeowner. [Conversely,] the majority [of produce sold by] the homeowner is not like the majority [sold by] the store-owner; what is permitted for the homeowner it forbidden for the store-owner. And this is the general rule: Whenever [foreign produce] forms the majority of it (i.e., of all produce of that species), it is permitted [to buy, sell, or consume without tithing], [and whenever foreign produce does] not form the majority of it, it is forbidden [to do so without tithing]. If [the foreign produce] formed the majority, and it diminished, the marketplace returns it to its former status (see Sanhedrin 19a:12 re "חזר...ליושנו"). Rabbi Yosei said, it so happened that a "threshing floor['s worth] of beans" entered Meron [from outside the Land of Israel], and they came and asked Rabbi Akiva, and he permitted them to [go to] the marketplace [to purchase the beans without tithing them as Demai, since the foreign beans formed the majority (see Minchat Yitzchak here)]. They [then] said to him, "Rabbi, it diminished" (i.e., the foreign beans are now the minority) and he said to them, "The marketplace has returned to its former status [and thus all produce must once again be treated as Demai]." Rabbi Shimon says, even if only a single "threshing floor" [of foreign produce] entered a city [and did not form a majority], the bakers are permitted [to sell it without first separating Demai (see Dem. 2:4)] because they "run after the new" (i.e., bakers only purchase new produce, so they need not measure new foreign produce against all domestic produce of that variety).