Yerushalmi Demai 5:6 ירושלמי דמאי ה׳:ו׳

MISHNAH: He who buys from a farmer and then buys from him a second time tithes from one batch for the other, even if they are from two crates, even if the are from two different hamlets⁹²If the farmer tithes, demay is a formality for all his produce. If he does not tithe, all his produce needs tithing and it is possible to tithe from one for the other.. If the farmer sells vegetables on the market, in case that his supply comes from his own vegetable gardens, one tithes from one for all others, from other vegetable gardens, one has to tithe each bunch separately.

HALAKHAH: Rebbi Jonah asked⁹³The entire discussion is about the farmer who sells not only his own produce on the market.: According to Rebbi Meïr, should he not tithe each stem separately? As we have stated there⁹⁴Mishnah Makhširin 6:2: “All bundled vegetables on the market are impure. R. Jehudah declares the fresh ones pure. R. Meïr said, why did they declare them impure? Only because of spittle!” The first Tanna holds that on the market one sprinkles water on the vegetables to keep them fresh. Hence, they are subject to impurity and, since everybody touches them, we must assume that an unclean person may have touched them and treat the vegetables as impure. R. Jehudah disagrees for those fresh vegetables which do not need refreshing; hence, they are not subject to impurity and it does not matter who touched them. R. Meïr restricts the impurity to bundles; since in binding them the farmer will have taken the string into his mouth the bundle was wetted intentionally, and, unless the farmer is a ḥaver, the bundle will certainly be impure. If the farmer is a ḥaver, the bundle still will probably become impure on the market.: “Rebbi Meïr said, why did it become impure⁹⁵Elided א, for טמאו.? Only because of spittle!” As you will say, there it is usual to open bundles and he⁹⁶The producer of the bundles. binds using his mouth, but here, is it usual to open bundles to risk⁹⁷Does the seller risk to open bundles? Is it not usual to have the good-looking vegetables outside and the lesser quality inside? Who would risk losing his sales by having less fresh vegetables visible from the outside? having the outer ones inside and the inner ones outside?

Rebbi Jonah said, not only from his own vegetable gardens, but even from vegetable gardens of others, if they tithe under his instruction⁹⁸Then all vegetables are either tithed or not tithed; in both cases, one can tithe demay without worry., he tithes from one for the other, but if they do not, he has to tithe each bunch separately.