[If] an am ha'aretz who said to a chaver, "Buy me a bunch of vegetables," [or] "[Buy me] a loaf of bread," Rabbi Yosei says, there is no need [for the chaver] to tithe [what he purchased for the am ha'aretz, see Dem. 6:12]. Rabbi Yehudah says, he needs to tithe. Rabbi Shimon ben Gamaliel says, if he exchanges the money (i.e., he uses his own money rather than the am ha'aretz's money to purchase the vegetables or the bread, see Minchat Yitzchak here), he needs to tithe.

[If] five said to one, "Go and bring us ten loaves of bread" [or] "[Go and bring us] ten bunches of vegetables," [and] he brings each one to his face (i.e., he brings that person what was purchased with that person's money), [then the] chaverim that are among them (i.e., among the purchasers) do not need to tithe except for their own portions. [But if] he brings them mixed together [so that he cannot tell which produce was purchased with which money], [then] the chaverim that are among them need to tithe on everything. If they gave him one in addition (i.e., the seller delivered one more item than was ordered, e.g., a baker's dozen), Rabbi Yehudah says, "It belongs to the messenger," and Rabbi Yosei says, "It is in the middle"*.

One who invites his friend to eat at his place, and [the friend] does not trust [the host] as to tithes, [the friend] says (i.e., makes the following declaration of intent) on Sabbath Eve (see Dem. 7:1, Kulp tr.): "What I will separate (alt., "What I will eat," see Lieberman) tomorrow, behold, it is tithes, and this [produce] is tithes for it, and what is nearest to it shall be the rest of the tithe. That which I made tithe will become terumat ma'aser, terumah taken from the entire produce for the whole, and the second tithe is to the north or to the south and it shall be exchanged for money." Said Rabbi Yehudah, "How is it that he can tithe something that has not come into his hand?" [But] Rabbi Yehudah concedes that he can go back and buy from the place that [the host] bought [the produce that will be served on Shabbat, and take tithes from that in exchange for what he will eat on Shabbat]. [If] they poured him a cup [of Demai wine], he says, "What I will leave at the bottom of the cup shall be tithe, and what is nearest to it shall be the rest of the tithe. That which I made tithe shall become terumat ma'aser for the whole, and second tithe is at the mouth of the cup, and it is exchanged for money."

A worker that was working at the place of a homeowner and [the worker] does not trust [the homeowner] as to tithes, Rabbi Yosei says, [this is the subject of] a ruling of the bet din, that he should take the priestly portion of the first tithe from [the portion of the produce] belonging to the homeowner, and the priestly portion of the second tithe from [the portion of the produce] belonging to the worker.

One who purchases [one hundred logs of] wine from Samaritans on Sabbath Eve [that he intends to drink on Shabbat], and he forgot to separate [tithes from it], says, "Two logs that I will separate in the future, behold, they are terumah, and the ten [logs] closest to them are first tithe, and the nine [logs] closest to them are second tithe." And he deconsecrates [the second tithe and transfers its sanctity to money], and he may drink it immediately [relying on the separation that he will perform later], the words of Rabbi Meir. (Sukkah 23b:5, Steinsaltz tr.) But Rabbi Yehudah, Rabbi Yosei and Rabbi Shimon prohibit [this]. They said to him, to Rabbi Meir, "Do you not concede that if the wineskin bursts [before he has tithed it], he will have drunk from untithed produce?" He said to them, "When it bursts, [I will be concerned]." (Sukkah 24a:6.)

One who had untithed figs inside his house, and he was in the house of study or in the field [may] declare, "Two figs that I will separate in the future, behold, they are terumah, and the ten that are closest to them are first tithe, and the nine that are closest to those are second tithe." [If] they were demai, he [may] declare, "What I will separate tomorrow, behold, it is tithe, and the remainder of the tithe is that which is next to it. That which I made tithe is [now] made terumat ma'aser on behalf of it (i.e., the remainder), and the second tithe is to the north or south of it, and it shall be exchanged for money*").

He takes terumah and terumat ma'aser and places it in a concealed location, and likewise for pure terumah as well as impure terumah (cf. Ter. 8:8).

A person should not drip oil inside a new candelabrum, and not inside a bonfire, and not inside any damaging agents, unless* he designates the terumat ma'aser that is in it before it [the oil] reaches the earth. Likewise, one who had ten casks of impure, untithed wine*, or of pure unithted [wine], and he sees that one of them spilled or was exposed, he [should] say, "Behold, I am making this terumat ma'aser on these nine [other casks]. But with regard to oil, he may not do this because of the Kohen's loss, and if he said, "Behold, this is terumat ma'aser [etc.]," he has not said anything.

[If] he saw someone that separated terumah and tithes and said, "I am hereby [separating] as much as he said," then his statement takes effect [and he is bound to comport himself according to the first person's declaration of intent]." Rabbi Yosei said, this [halachah] is in reliance on a ruling [handed down by] the beit din.

One who gives too much in tithes, his tithes are in good order but his produce is ruined (i.e., for consumption). One who gives too little in tithes, his tithes are ruined but his produce is in good order.

One who designates the dregs [at the bottom of] a barrel [of wine as terumah and tithes], he is forbidden from drinking from the mouth [of that barrel of wine). [One who designates the wine that is at] the mouth [of the barrel as terumah and tithes], he is forbidden from drinking from the dregs [of the barrel], because liquids become mixed [and therefore, he consecrates the entire barrel by designating any part of it as terumah and tithes]. But one who designates the "dregs" of a storeroom* [of grain] may eat from the "mouth" [of the storeroom], [and one who designates] the "mouth" [of the storeroom] may eat from the "dregs" [since dry produce does not mix together].

There were before him two baskets of tevel (i.e., untithed produce, Dem. 7:6): In this [basket] one hundred and in that [basket] one hundred. He took terumah from both of them, and [then] says, "the tithes from this one are in that one," the first [basket] is thus tithed. [If he says,] "[the tithes from] this one are in that one, and [the tithes from] that one are in this one," the first one is not tithed. He [thus] takes two figs [and] two tenths, and a tenth of a tenth. [If he said,] "The tithes of each basket are in the the other [basket]," he has [properly] designated [the tithes of both baskets], [and] he takes twenty figs from whichever one of them he desires [as tithes]. [If there are] one hundred in this [basket] and two hundred in [that basket], then if he takes [tithes] of the smaller [basket out of the larger basket], he takes out eleven, and if he takes [tithes] of the larger [basket out of the smaller basket], he takes it all out [and] he [still] has not fulfilled [his obligation]. [If there are] one hundred in this one and one thousand in that one, then if he takes [tithes] of the smaller [basket out of the larger basket], he takes out fifteen, and if from the larger [basket out of the smaller basket] he takes out all sixty from this one and afterwards [finishes taking] according to the calculation.*

If he had in his hand a basket of fruits that were not tithed, he takes two ninths of this one and one ninth of that one. Of the one ninth, whether untithed produce predominated over chullin produce, or vice-versa, he takes all the chullin according to the proper amount of terumat ma'aser that is in the untithed produce. Whether the ma'aser tevel predominated over the chullin, or vice-versa, he takes all the chullin according to the proper amount of terumat ma'aser that represents the tithes of the untithed produce. [If he had] 180 untithed produce, he takes 92 less one tenth. [If he had] 100 [of untithed produce and desires to] take tithes, he takes 93 less two tenths from this, and the remainder according to his calculation.

One who separates a log of untithed food on behalf of 99, he says, "A log which is in the dregs (the bottom) of the flask, behold it is chullin and the remainder is terumah on everything."

Someone who had two barrels [of wine] -- one of impure ma'aser tevel (tithes separated from certainly untithed produce) and one of pure ma'aser tevel (see Y. Dem. VII.8.3) -- [and he does not know which one is which], he brings two small vessels and fills from this one terumat ma'aser on behalf of both of [the barrels], and from that one the appropriate amount of terumat ma'aser on behalf of both of them. He then goes to the first [vessel], and says, "If this [wine] is from the impure [barrel], I have not said anything, but if this is from the pure [barrel], I am making [this vessel] terumat ma'aser on behalf of both of them." He then goes to the second [vessel], and says, "If this is from the impure [barrel], I have not said anything, and if it is from the pure [barrel], I am making [this vessel] terumat ma'aser on behalf of both of them. " [In that way,] he has designated the first [as pure], and he has returned and designated the second [as pure], and as a consequence both barrels are [deemed to have been] tithed. One vessel [is deemed to consist] of impure ma'aser tevel, and the other vessel of pure ma'aser tevel. [A Kohen may] drink from this one, and immerse himself [in a mikveh], and [then] drink from that one and immerse himself, and [then] drink from both of them at once, and he needs to immerse himself one last time.

Someone who had two barrels [of wine] -- one of impure (alt. "pure," per MS Erfurt) ma'aser tevel and one of pure unconsecrated [wine] -- he brings two small vessels and fills from this one the appropriate quantity of terumat ma'aser on behalf of that one, and from that one terumat ma'aser on behalf of this one.* He then goes to the first [vessel], and says, "If this one is impure, I have not said anything, and if this one is from the pure [barrel] I am making [this vessel] terumat ma'aser on the other [vessel]." He then goes to the [second] vessel, and says, "If this is from the impure [barrel], I have not said anything, and if it is from the pure [barrel], I am making [this vessel] terumat ma'aser on the other [vessel]. " He designates the first, and he returns and and designated the second, and consequently both barrels [are deemed] tithed, and one vessel is of impure ma'aser tevel, and the other of pure unconsecrated [wine]. [A Kohen may] drink from this one and immerse himself, and [then] drink from the other one and immerse himself, and [then] drink from both of them at once, and he needs to immerse himself one last time.