(Baraisa): When Yehoshua conquered the Land, he made 10 conditions - one of them was that one is permitted to pick herbs from any field, except a fenugreek field.

(R. Yaakov bar Acha citing R. Yitzchak bar Nachman): The Baraisa is discussing when he planted it for its stalks.

Question: (How could fenugreek be prohibited?) Doesn't our Mishnah teach (Menachos 35 (d)) that if a fenugreek field sprouted many species of herb - he is not obligated to weed them (since they cause damage to the fenugreek and the owner doesn't want them)?

(R. Yaakov bar Acha himself): It's when he planted the fenugreek for it to be used for sowing (When the herbs grow there they cause damage so he does not want them to grow and it is not Kilayim. However, Yehoshua prohibited using herbs from a fenugreek field when they were planted for animal fodder, where he is happy if herbs grow.)

Question (R. Yosi): Did Yehoshua come to explain it for the benefit of sinners? If a person had sinned (and planted fenugreek for animal fodder and allowed the herbs to grow), other may not take it as it is theft. But if he had not sinned (in allowing the herbs to grow, as the fenugreek had been used for sowing or for human consumption), others may take it as there's no problem of theft.

Answer: It makes no difference whether he used them for sowing or for animal fodder (as in both, he wants the herbs uprooted. If so, why did Yehoshua prohibit picking from such a fenugreek field?)

Question: (And furthermore,) our Mishnah taught - 'if a fenugreek field sprouted many species of herb - he is not obligated to weed them'. But if you say that his mind is on them, he would need to uproot the herbs?

Answer (R. Acha citing R. Maysha): The owner doesn't want them, but once they have already grown and damaged the fenugreek, he then wants them for use and it's as if they were already uprooted and set down before him.

Question: If so, the same should apply to Kilay HaKerem (crops that grew in a vineyard) that it would be theft to take them?

R. Yosi disagreed with R. Acha - rather, when they are growing and even when he picks them, he doesn't want them (which means that they are permitted), but later on he will want them.

Question: If so, Kilay HaKerem should be prohibited to steal, since he wants them in the end?

Answer: In a fenugreek field, it would be gathered in together with the herbs since they are both used for animal fodder; in a vineyard, it would not, (since the grapes are for human use).

(Rav Nachman): R. Mana asked - if he had another field of fenugreek near the vineyard, it would be forbidden to uproot the herbs that grow in the vineyard, as he would gather them together with the fenugreek...? (The Gemara leaves this question unanswered.)

The Rabbanan disagree with R. Yosi (who said that in a fenugreek field, he wants the herbs after they are picked, but there is no prohibition of Kilayim, whether they were sown for seeds or for animal fodder) - as R. Zerikan said from Beis R. Yannai - All Sefichin are prohibited, aside from those that grow in a fallow field, a plowed field and a vineyard; and some say aside from a fenugreek field that was sown for its seeds (since the Sefichin do damage).

(R. Yosi): A teaching of R. Yochanan supports me - it once happened that a person bought all the vegetables of a garden from a gentile (in which Kilayim were planted). R. Yochanan told him, "Go and uproot the Kilayim (as if you leave them growing in your possession, they will become prohibited) and find out their value and sell them".

Question (R. Abahu to R. Yochanan): But the Mishnah taught, "or an area of a threshing floor that sprouted many species (that damage the ground)". (The vegetables there don't become Kilayim as all are aware that he is unhappy about them - so why here must he immediately uproot them)?

Answer (R. Yochanan): There, it's location (the threshing floor) proves that he doesn't want them.

(R. Yosi): If there would be a difference as to whether he planted the fenugreek for human or animal consumption, he should have used it to answer that in the case of R. Yochanan, he may not collect the herbs because it's theft; and in the Mishnah where he's not happy with its growth, there is no prohibition. And R. Yochanan should have responded, "How can you question me from a case where there's no prohibition of theft?" (And since he didn't respond in this way, he must reason that even if herbs grew in a fenugreek field that was planted for human consumption, he is happy with it.)

Rebuttal: It's like the statement of R. Imi, that R. Yochanan had many answers (but he just chose one of them), or we can say like R. Nasa, that it's like a person that has two answers to give and only gives one of them.