Machshirin 2:9 - 2:10

הולכין אחר רוב טבחין – if the majority are Israelite butchers, the meat is permitted. For the Halakha is not according to Rav who stated that meat that was concealed from the eye is prohibited. But Rav establishes our Mishnah with regard to a case where a person stands and sees from the time that it (i.e., the meat) is slaughtered until it fell, but he did not know who slaughtered it.

אם רוב מכניסין לבתיהן פטור - from tithing (see also Tractate Maaserot, Chapter 1, Mishnah 5).

למכור בשוק חייב – that the majority brings [produce] to sell in the marketplace, it is from the house they bring it, and it is already liable [for tithing]. Another explanation: If the majority [of people] bring it into their homes, they are exempt [from tithing] because they regularly tithe prior to bringing it into the house in order that they would be able to eat from them [other than a snack/incidental meal]. For after they brought them into the house, they have immediately become susceptible for tithing. Therefore, what falls from them on the path/road is exempt from tithing, because it is under the presumption of having been tithed, but when they bring them [into the marketplace] to sell, it is the manner to bring them in as eatables forbidden pending the separation of sacred gifts/טבל, because one is able to eat from them an incidental meal/snack, therefore, that which falls from them is not under the presumption of being tithed.

אם רוב נכרים ודאי – Rabbi Meir, according to his reasoning, who holds that there is no acquisition [of land] for heathens in the Land of Israel to release them from tithing, and produce that grew in the fields of heathens are liable for tithing, for the heathen simply did not tithe, therefore, they are definitely eatables forbidden pending the separation of sacred gifts/טבל.

ואם רוב ישראל דמאי – according to the law of produce that is found in the hands of commoners [who are generally observing certain customs regarding tithes and Levitical uncleanness], that one needs to separate from them the tithe of the tithe (i.e., the tithe that the Levite gives to the Kohen) and the Second Tithe.

וחכמים אומרים וכו' – the Sages hold that there is acquisition [of land] for heathens in the Land of Israel to release them from tithing. But there wasn’t an Israelite who would put [his produce] into it (i.e., the storage bin). Everything is doubtfully tithed, for the produce of that Israelite, for they (i.e., the produce) is liable [for tithing]. And the Halakha is according to the Sages.