Bikkurim, Chapter 1, Mishnah 7. The Mishnah discusses someone who separated bikkurim from his field and afterward sold that field: "HaMafrish bikkurav umachar sadehu - mevi v'eino korei" - one who separates his bikkurim and then sells his field brings them but does not recite.
Bringing without reciting:
The case is someone who sold his only field, so that he no longer owns any land at all. Since he owns no land, he cannot say the passage of the recitation. The Mishnah therefore rules that he brings the bikkurim, since at the time of separation the land was still in his possession, but he does not recite, since by the time he brings them he no longer owns land.
The Yerushalmi points out, as we mentioned in the previous Mishnah, that this applies specifically where he was already about to sell the field at the time of separation, so that from the outset there was no expectation of a recitation, since it was known in advance that no land would remain in his hands. But if he separated them intending to recite, and only afterward sold the land in a way that made recitation impossible, he would not be able to bring the bikkurim at all, and they would be left aside until they rotted.
The status of the buyer:
The Mishnah continues and discusses "v'hasheini" - the second one, the buyer who purchased that very field. Does he bring bikkurim after the seller has already separated them? The Tannaim disagree about this:
Tanna Kamma: "me'oso hamin eino mevi, mimin acher mevi v'korei" - from the same type of fruit from which bikkurim were already separated the buyer does not bring; but from another type growing in that field he brings and recites.
Rabbi Yehudah: "af me'oso hamin mevi v'korei" - even from the very same type of fruit that the seller brought, the buyer brings and recites.
The basis of the dispute - "higadti hayom":
In the passage of the recitation the Torah says "higadti hayom" - "I have declared today", and from here we learn that a person declares once and does not declare twice. The disagreement is built on this:
According to the Tanna Kamma: the buyer does not bring from the same type that the first owner brought, since that would amount to doing the thing twice. Even though no double recitation actually took place here, since the first person never recited, nevertheless bikkurim would be brought twice from the very same type, and that is not permitted. From a different type, however, the idea of doing it twice does not apply at all.
According to Rabbi Yehudah: the rule that a person brings and recites only once and not twice was said about a single person only. One person does not bring twice, but two different people do bring. Therefore the buyer brings and recites even from the very same type of fruit.
In summary: in this Mishnah we learned that one who separates bikkurim and then sells his field brings them but does not recite, and according to the Yerushalmi this is specifically where he was already about to sell at the time of separation. Regarding the buyer there is a dispute: according to the Tanna Kamma he does not bring from the same type but brings and recites from another type, while according to Rabbi Yehudah he brings and recites even from the same type, since the rule learned from "higadti hayom" was said about one person and not about two people.