Meilah, Chapter 3, Mishnah 7. Our chapter continues its long list of items that a person may not use, and yet, if he did use them, he has not transgressed the prohibition of me'ilah. The mishnah now applies that principle to four cases: the roots of a tree that grow across a property line, a spring whose waters pass through consecrated ground, the water prepared for the water libation on Sukkot, and the willow branches used at the mizbeach.
How Far Does a Tree Reach?
The opening case rests on a halachic measurement. A tree feeds itself through those roots that lie within sixteen amot of its trunk, and halachah treats such roots as a limb of the tree itself, the property of whoever holds title to the tree. Roots that run out past that sixteen amah radius are no longer reckoned as the tree at all; they follow the earth in which they sit, and title to them passes to whoever holds that ground.
Now imagine a consecrated field and an ordinary privately owned field sharing a boundary, with a tree standing near the line whose roots pass underneath it. On this the mishnah teaches: "Shorshei ilan shel hedyot" , the roots of a tree that belongs to a private individual, "ba'in beshel hekdesh" , which run across into consecrated ground; "veshel hekdesh ba'in beshel hedyot" , and the reverse case, roots of a tree belonging to hekdesh that spread into an unconsecrated field. In either direction the ruling is "lo nehenin velo mo'alin": taking benefit from such roots is barred, and yet one who did take benefit has not fallen into me'ilah.
The First Case: A Private Tree, Hekdesh Soil
Here the tree belongs to an ordinary owner, and we are speaking specifically of roots lying within sixteen amot of the trunk. Since those roots are part of his tree, they remain his property even though they are physically situated in consecrated ground. There is no consecrated object here at all, so me'ilah cannot apply. Still, one may not make use of them, because to the eye it appears that a person is helping himself to hekdesh.
Roots of that same private tree that reach more than sixteen amot into the hekdesh field are a different matter entirely. They are no longer considered part of the tree, so they follow the ground in which they grow, and me'ilah applies to them in the ordinary way.
The Second Case: A Hekdesh Tree, Private Soil
Now the tree itself belongs to hekdesh, and its roots have spread into an unconsecrated field. The mishnah is speaking of roots farther than sixteen amot from the trunk. Because of that distance they are not reckoned as part of the tree, and therefore me'ilah does not apply to them. Nevertheless, they grow out of a tree that belongs to hekdesh, and on that account the rabbis forbade deriving benefit from them.
By contrast, roots of the hekdesh tree that lie in the private field within sixteen amot of the trunk are genuinely part of the consecrated tree, and me'ilah applies to them in full.
A Spring That Passes Through Hekdesh
The mishnah turns to a comparable situation with water: "Hama'ayan shehu yotzei mitoch sdei hekdesh, lo nehenin velo mo'alin." A spring rises in ordinary private property and its waters flow onward through a field belonging to hekdesh. While the water is inside the boundaries of the hekdesh field one may not benefit from it, but one who does benefit has not violated me'ilah, since the spring itself was never consecrated. The rabbinic prohibition stands for the same reason as before: a person drawing from that water inside the consecrated field looks as though he is using hekdesh.
"Yatza chutz lasadeh, nehenin mimenu." Once the water has left the hekdesh field, it may be used freely.
The Water of the Nisuch Hamayim
The following case concerns the water poured upon the mizbeach throughout Sukkot, the nisuch hamayim, which accompanied the daily wine libations. Its water was drawn at the Shiloach, a spring situated beyond the walls of Yerushalayim. On every day of the festival a golden jug, a tzluchit that had the status of a keli sharet and was therefore holy, was filled there, carried up to the Beit Hamikdash, and its contents poured upon the mizbeach.
Shabbat demanded a different arrangement, for the water could not be transported from the Shiloach across a reshut harabim on that day. It was accordingly drawn on Friday and kept in the Mikdash through the night. Here a difficulty arose: whatever is placed into a keli sharet becomes vulnerable to the pesul of linah and cannot be held over until morning. The remedy was to draw the water into a golden barrel that had never been consecrated, a vessel that imparts no kedushah to what it holds, and to leave the water standing in it overnight. When Shabbat morning came, the water was emptied into the holy golden jug and poured upon the mizbeach.
The mishnah rules on the status of that water: "Hamayim shebekad shel zahav, lo nehenin velo mo'alin." Water sitting in the golden barrel may not be used, since it has been set aside for the service of hekdesh, yet one who used it has not transgressed me'ilah, because the barrel never consecrated its contents. "Nitno batzluchit, mo'alin bahen." Once the water was poured into the golden jug, the keli sharet, it became consecrated, and from that moment me'ilah applies to it.
The Aravah at the Mizbeach
Another ceremony of Sukkot was the aravah. Each day large willow branches were brought and stood up against the walls of the mizbeach, and the kohanim would circle the mizbeach reciting praises to Hakadosh Baruch Hu. May one benefit from those branches?
The mishnah's ruling is "Aravah, lo nehenin velo mo'alin." Those willows, having been set aside for the Sukkot ceremony of the Mikdash, are off limits for a person's private use, yet someone who did take benefit from them has not transgressed me'ilah, since the branches themselves carry no kedushah.
Rabbi Elazar the son of Rabbi Tzadok preserves a practice from those days: "Notnin hayu mimena" , a portion of the branches was handed out, "lezkeinim belulaveihen" , to the elders, who tied them together with their lulav and hadassim. This took place before the willows were leaned against the sides of the mizbeach. The elders found it hard to come by aravot of their own, so they took from the supply brought for the Mikdash and discharged with them their obligation of arba'at haminim. Private benefit from these branches is forbidden, but employing them for a mitzvah is another matter, for mitzvot lav lehanot nitnu: performing a mitzvah does not register as deriving benefit.
Rabbi Elazar beRabbi Tzadok is therefore not arguing with the Tanna Kamma. The Tanna Kamma likewise holds that the aravot could be taken for the mitzvah. All agree that ordinary benefit is forbidden, and all agree that fulfilling a mitzvah with them is not considered benefit at all.