As we learned above (daf 69) the Mishna taught what is included in the standard sale of a field, and distinguishes between different trees – ḥaruv she-eino murkav vs. ḥaruv ha-murkav – a carob tree that has not yet been grafted and one that has, and betulat ha-shikma vs. sadan ha-shikma – a wild sycamore tree and one that has been trimmed. According to the Mishna, these trees in their natural state are considered part of the field and are sold with it, but once they have been cultivated in different ways, they are independent and will not be sold with the field unless it is specified in the sale agreement.
The Gemara on today’s daf brings Rav Huna’s teaching that the ḥaruv ha-murkav and the sadan ha-shikma are not totally independent from the ground, in fact, with regard to some issues they are independent trees, but with regard to others they are part of the field. Specifically, as we learned in the Mishna, these trees will not be sold incidentally to the field, but will remain independent of it, and be considered “real estate” on their own. On the other hand, if two other trees were sold together with one of these, the three trees together will merit a plot of land that will support them.
The point of Rav Huna’s teaching is that we should not think that the individual importance of the ḥaruv ha-murkav and the sadan ha-shikma makes them lose their status as trees, rather they remain trees with regard to the laws having to do with trees.
Rav Huna applies this logic to other cases as well, for example, application of the laws of shikh’ḥa. Ordinarily shikh’ḥa – a biblical requirement to allow the poor to take a forgotten sheaf or two of harvested grain (see Devarim 24:19) – must be left for the poor, but sheaves that have unique status do not fall into this category, since they will be remembered by the owner who will come back for them. So if a uniquely large sheaf is left behind it retains its special status and is not considered shikh’ḥa, but if there are two others with it, they are considered to all be ordinary sheaves, and none will be left for the poor, since three sheaves are not considered shikh’ḥa.