1) ONE WHO CONSECRATES THREE TREES TO HEKDESH
OPINIONS: The Gemara quotes a Beraisa which discusses the case of a person who is Makdish trees and the land upon which they stand. If he is Makdish three trees, which are somewhat close to each other, at one time, the land beneath them also becomes Hekdesh, just as the land is included in the sale of three trees. Accordingly, one who wants to redeem the property must redeem the trees and the land together, as one unit. In contrast, if he is Makdish trees at separate times, one after the other, Hekdesh does not acquire the land and the trees are considered individual units when one redeems them. The Gemara adds that even if the trees were made Hekdesh and then the land was made Hekdesh, the land must be redeemed separately from the trees. (This increases the redemption-value of the trees.)
To what exactly does last case in the Beraisa refer? Does it refer to one who is Makdish three trees at the same time or independently?
(a) The RASHBAM (DH v'Lo Od) explains that the Beraisa refers to one who is Makdish the trees separately. Apparently, the Rashbam's reasoning is that if all of the trees are made Hekdesh together, the land also should become Hekdesh, and the trees and the land should be considered one unit with regard to their redemption.
The RASHASH asks that if this is what the Beraisa means, then it should not have presented this case as a separate case, but it simply should have added to the previous case and said that the law applies even when the owner makes the land Hekdesh as well. Why does the Beraisa need to state a new case?
(b) The Rashash therefore explains that the Beraisa refers to a case in which the owner makes the trees Hekdesh all at once, and in the same statement he proclaims the land Hekdesh as well. The fact that the owner says that the land is Hekdesh implies that he did not include the land in his original statement that the trees are Hekdesh. Accordingly, his two statements of Hekdesh are two separate declarations. The Beraisa is teaching that in such a case the trees and land are viewed as separate units of Hekdesh, and thus they must be redeemed separately. (Y. Montrose)

72b----------------------------------------72b

2) WHY ARE THREE BUNDLES NOT CALLED "SHICHECHAH"
OPINIONS: The Gemara teaches that when a bundle contains two Se'ah of produce, sometimes it has the Halachic status of an "Omer" ("sheaf") and sometimes the status of a "Gadish" ("pile"). It is considered a sheaf with regard to the Halachah that when three sheaves are found within close proximity of each other, they are not Shichechah. Produce is considered Shichechah only when it is two sheaves or less. When there are two sheaves in close proximity to the large bundle that contains two Se'ah, the sheaves are not considered Shichechah. Nevertheless, when the large bundle with two Se'ah is found by itself, it has the status of a Gadish, pile, and not a sheaf, and it is not considered Shichechah.
What is the source for the Halachah that produce is Shichechah only when there are less than three normal-sized sheaves in one area?
(a) The RASHBAM (DH Shnei Omrim) quotes the Sifri which derives this Halachah from the verse, "v'Shachachta Omer ba'Sadeh" -- "and if you forget a sheaf in the field" (Devarim 24:19). This implies that only when the amount forgotten is a sheaf does it have the status of Shichechah, but not when it is a pile. This is also the opinion of the ME'IRI.
(b) The RAMBAM (Hilchos Matnos Aniyim 5:14) gives a different source. He explains that this Halachah is derived from the verse, "l'Ani vela'Ger Ta'azov Osam" -- "for a poor person and a convert you shall leave them" (Vayikra 19:10). This verses teaches that Shichechah constitutes one sheaf for the poor person and one sheaf for the Ger, or up to two sheaves. Three sheaves, however, does not constitute Shichechah. The DERECH EMUNAH points out that the Rambam's source is mentioned in the Yerushalmi.
(c) The SEFER HA'YERA'IM gives a different reason for why three sheaves are not Shichechah. He explains that the status of Shichechah depends on whether the produce is something that the owner might forget, such as one or two sheaves of wheat. Three sheaves of wheat, in contrast, is something that the owner would notice is missing and will eventually "remember" them. Three sheaves therefore do not constitute Shichechah. (Y. Montrose)