Talmud zu Maaser Sheni 3:3

MISHNAH: If somebody had coins in Jerusalem and his friend had produce³⁷The coins are tithe money, the produce is profane. By the declaration, the produce becomes Second Tithe and has to be eaten in purity but the coins are profane and may be used for business., he says to his friend, these coins are exchanged for your produce. That one has to eat his produce in purity but he can use his coins for his needs. But one should not say this to a vulgar unless they were from demay³⁸The vulgar cannot be trusted to eat anything in purity; see the Introduction to Demay. Second Tithe from demay is only conditional tithe; it is not sure whether it really has to be eaten in purity. Therefore, it may be exchanged for produce of the vulgar..
Produce in Jerusalem and coins in the countryside, he says these coins are exchanged for that produce. Coins in Jerusalem and produce in the countryside, he says that produce is exchanged for these coins; then the produce must be brought to and eaten in Jerusalem³⁹The only exchange prohibited is that of Second Tithe produce in Jerusalem..
[Tithe] money enters Jerusalem and leaves; [tithe] produce enters but does not leave. Rabban Simeon ben Gamliel says, even produce enters and leaves.
If fully processed produce was transported through Jerusalem, its Second Tithe should be brought back and eaten in Jerusalem⁵⁷Even outside of Jerusalem it cannot be redeemed since tithes should have been separated before it was transported to Jerusalem.. If the produce was not fully processed, the baskets of grapes are for the wine-press, and baskets of figs for the muqẓeh.
The House of Shammai say, the Second Tithe should be brought up and eaten in Jerusalem⁵⁸In most Mishnah mss. this Mishnah is part of the preceding one and continues the preceding text. Even though no tithes were due at the time the produce was in Jerusalem, the influence of Jerusalem is so great that even potential tithe cannot be redeemed.. But the House of Hillel say, it may be redeemed and eaten anywhere. Rebbi Simeon ben Jehudah⁵⁹A Tanna of the fifth generation, the most important student of R. Simeon bar Ioḥay. Sometimes, he is called R. Simeon ben Jehudah from Kefar Akko. said in the name of Rebbi Yose, the House of Shammai and the House of Hillel did not disagree about produce which was not fully processed, that its Second Tithe may be redeemed and eaten anywhere. Where did they disagree? About fully processed produce, where the House of Shammay said, its Second Tithe should be brought back and eaten in Jerusalem, but the House of Hillel said, it may be redeemed and eaten anywhere. Demay enters, leaves, and may be redeemed⁶⁰This statement is part of the statement of R. Simeon ben Jehudah. According to R. Simson and Maimonides in his Code (Ma‘aser Šeni2:9), it is agreed that tithe from demay produce which passed through Jerusalem may be redeemed anywhere but Second Tithe from demay may not be redeemed in Jerusalem. In his Commentary, Maimonides refers to Mishnah Demay 1:2 and frees Second Tithe of demay from the rules of Mishnaiot 4–7; this contradicts Halakhah 6..