(Mishnah): If he said, "...on condition that I have a Beis Kur (a field large enough to plant a kur = 30 seah) sized piece of land'' - she is betrothed if he has it (i.e. if he has witnesses that he has the land; but without witnesses, she is only doubtfully betrothed).

"...on condition that I have (it) in a certain place'', if he has it there, she is betrothed; if not, she is not betrothed.

"On condition that I show you a Beis Kur sized piece of land'', she is betrothed and he must show her. But if he showed her (ownerless) land in a valley (or even land upon which he works as a sharecropper), she is not betrothed.

R. Meir: Any condition that is unlike the condition given to the children of Gad and Reuven (i.e. where both possibilities are expressed) is not a valid condition, as the pasuk states (Bamidbar 32, 29), "And Moshe said to them - if the children of Gad and the children of Reuven shall cross...and if they shall not cross etc.''

R. Chananya ben Gamliel: (One cannot make this deduction as) it needed to be said that way (stating both the positive and the negative) - otherwise it would have implied that they shall not even inherit (a portion of) the Land of Israel.

(Gemara - Question - R. Chananya son of R. Hillel): According to R. Chananya ben Gamliel, even though one could deduce the negative from the positive that they would not take a portion of Gilad, one would never deduce that they would not even take a portion of the Land of Israel since there had been no mention that the other tribes were going to inherit it...?

Answer: It is different here since the pasuk states (Bamidbar 34, 13), "...to give to the 9 1/2 tribes etc.'' - therefore, it is logical to deduce that if they do not (fight in the wars), they will not take a portion even in the Land of Israel.

Mishnah in Maseches Eiruvin: "A person may make his Eiruv conditional (depending the Eiruv on the direction to which he will need to flee from the city on Shabbos if gentiles attack. He puts down two Eiruvs, one to the east of the city and one to the west and through his condition in which he verbalizes each option, he validates one of them)''. So the Mishnah should actually say, "a person may make his Eiruvs conditional'' (since he is in fact putting down two of them).

R. Elazar: If so, who is the author of this Mishnah? It is R. Meir who requires a condition to be verbalized both ways.

Question: To which statement of R. Meir are you referring?

Answer (Chevraya): R. Meir in the Beraisa about Kidushin - One who say to a woman, "Behold, you are betrothed to me on condition that it shall rain''. If it rained, she is betrothed; if it did not rain, she is not betrothed. R. Meir says - whether or not it rained, she is betrothed unless he verbalized his condition both ways. All agree that if he said that she will be betrothed after it rains, then if it rained they are betrothed and if not, they are not betrothed.

R. Yosi: We are referring to R. Meir in Maseches Eiruvin, where it teaches that (if the Eiruv rolled out of the Techum and it is doubtful whether it rolled there before Shabbos, thereby invalidating it, or on Shabbos) R. Meir and R. Yehudah both say that he must be stringent both ways (that he cannot walk in the extra area created by the Eiruv, nor can he walk in the area of his town's perimeter excluded because of his Eiruv.

R. Yosi: R. Meir only said his ruling (that one must make a double condition) as a stringency (in kidushin because of the severity of the laws of forbidden relationships, but in other subjects such as Eiruvin, he does not require it).

R. Mana: This is certainly correct - in Eiruvin, the reason that he is stringent is that perhaps the Eiruv rolled outside of the Techum before Shabbos and he also cannot be as an inhabitant of his town since this was not his intent at the onset of Shabbos as he thought he had successfully made an Eiruv. But here, in kidushin, if another man came and betrothed her before it rained, she is married to neither - the first one because it did not rain and the second one because he did not make the condition dual. Nevertheless, we rule stringently that perhaps the condition is invalid and she is therefore married to the first one even if it did not rain.

Question (R. Chagai to R. Yosa): Why did "if not'' said by Moshe (in the phrase "if they shall not cross'') need a dual condition but the "if not'' of Eiruvin did not require it?

Answer: For Moshe it was different as the land of Gilad (in the Transjordan) was already in their possession and Moshe wished to potentially expel them.

R. Yudah bar Sisin/ R. Yudah bar Pazi citing R. Acha: They established that simfons should be written with a double condition in accordance with the view of R. Meir in Kidushin.

Question (R. Chananya, friend of the Rabbanan): Why is this only in accordance with R. Meir? It is even in accordance with the Rabbanan!

Answer: Did R. Abahu not cite R. Yochanan (earlier) as saying that the text of a simfon is - "I, ploni son of ploni, betroth you, plonis daughter of plonis on condition that I will give you the sum of money as written and I will perform with you nisuin on day ploni. If day ploni comes and I do not perform nisuin with you, I have no claim against you (and the betrothal is annulled).'' However, according to the Rabbanan, there would be no need to double the condition!

Rebuttal: Even according to the Rabbanan, if he would not double the condition, the simfon would not be able to annul the kidushin since it is already in place.

R. Yosi bei R. Bun: In all cases except here, R. Meir says that one can deduce the positive from the negative.

R. Matanya: This is because of the severity of forbidden relationships.