Meilah 18A

מתני׳ הערלה וכלאי הכרם ⁠– מצטרפין זה עם זה. רבי שמעון אומר: אין מצטרפין.

Mishnah: The fruit of a tree during the first 3 years after its planting [orla] (see Leviticus 19:23), and diverse kinds,i.e., grain sown in a vineyard (see Deuteronomy 22:9) join together to constitute the requisite measure to prohibit a mixture that they are mixed into. This applies when the volume of the permitted produce is less than 200 times the prohibited produce. R' Shimon says: They do not join together.

גמ׳ ומי צריך רבי שמעון לצרופי? והתניא, רבי שמעון אומר: כל שהוא למכות? תני: אין צריכין לצרף.

Talmud: The Talmud asks: And according to R' Shimon, do the two half-measures need to join together, in order for one who eats them to be liable? But isn’t it taught in a baraita that R' Shimon says: One who eats any measure of a prohibited food is liable to receive lashes, as the rabbis stated the measure of an olive-bulk only with regard to the requirement to bring an offering? The Talmud answers: The wording of the Mishnah is not precise and must be emended, to teach that R' Shimon says: They do not need to join together, as one is flogged even for less than the minimum measure.

מתני׳ הבגד והשק, השק והעור, העור והמפץ ⁠– כולן מצטרפין זה עם זה.

Mishnah: A garment must be at least 3 by 3 handbreadths in order to become a primary source of ritual impurity, by means of ritual impurity imparted by the treading of a zav. A sack made from goats’ hair must be at least 4 by 4 handbreadths, while an animal hide must be 5 by 5, and a mat 6 by 6. The garment and the sack, the sack and the hide, and the hide and the mat all join together to constitute the requisite measure to become ritually impure in accordance with the material of the greater measure.