What does "Sharerech Agan ha'Sahar" refer to?
Rashi according to the metaphor, from Sanhedrin 37a: It refers to the Great Sanhedrin. It is called Sharerech (navel) because it sits (in Lishkas ha'Gazis, a chamber in the Mikdash,) in the middle of the world. It is called "Agan" for it is Magen (protects) the entire world. "Ha'Sahar" - they sit in a (semi-) circle, like the Sahar (moon).
Rashi: Your navel is Agan (a bowl) of clear water to bathe in. It is made of marble stones. It is called Sahar in Arabic, for the navel is like a round hole, it is compared to a round bowl. This praise is not beauty of a woman, like above, for above her Beloved praises her, and here her colleagues praise her for her deeds - you are proper to connect with us.
Seforno: The Great Sanhedrin sits like a round half-Goren (a moon crescent), and they can remove all arguments.
Malbim (Melitzah): Your navel is like Agan ha'Sahar, which is always full of beverages. It sends its springs to all limbs.
What do we learn from "Al Yechsar ha'Mezeg"?
Torah Temimah citing Sanhedrin 37a: One may leave the Sanhedrin only if at least 23 (the size of a small Sanhedrin) will remain. (This is about a third, like pure wine is a third of the Mezigah (after it is mixed with water.)
Rashi: Drinks will not be finished from there. I.e. rulings will not cease from there.
Seforno: The Sanhedrin's decision between the opposing opinions, do not let it lack Bnei Bavel (may they return to Eretz Yisrael)! Now, your stomach (Chachamim, who are like the stomach, which sends food and Ru'ach Chayim to the rest of the body), is like a stack of wheat fenced with roses. Nothing unites it to be one, rather, it is piles and piles - Torah is like two Toros.
Malbim (Melitzah): With death, the flask will be broken on the spring, and this mixing (sending to all the limbs what they needs) will cease. The Kli (Agan) will be useless.
Malbim (Mashal): You are used to drinking wine to satiation in Beis ha'Melech. Do not go to the house of the poor shepherd, for there you will lack wine!
What do we learn from "Bitnech Aremas Chitim"?
Torah Temimah citing Sanhedrin 37a: Just like all enjoy wheat, all enjoy the reasons that the Sanhedrin gives.
Rashi: Everyone needs [the Sanhedrin, just like they need wheat].
Malbim (Melitzah): Do not let Aremas Chitim be lacking - after death, wheat will not be given to the mill (stomach) to grind.
Malbim (Mashal): You are used to having enough wheat to fill the stomach in Beis ha'Melech. You will not have this in the house of the poor shepherd!
Why does it say "Sugah ba'Shoshanim"?
Torah Temimah citing Sanhedrin 37a: How could Chachamim permit a Nidah to be secluded with her husband? Will a fire not singe chips (can he control his desire)?! The Torah testified about Yisrael "Sugah ba'Shoshanim" - Yisrael do not breach even a wall of roses 1 (Rabbinical enactments).
Malbim (Melitzah): There are many beautiful flowers prepared to receive the food, grind it and send clarity of the blood to the organs that digest and divide it among all conduits of the body.
Rashi: A Chasan enters the Chupah longing for his Kalah. He comes to be intimate with her, and she tells him that she saw a tiny drop of blood the size of a mustard seed; he turns away. A snake or scorpion did not bite him! He was going on the road, and saw Bechoros (the first figs to ripen) on top of the tree. He stretched his hand to take, and they tell him, they are of a Yisrael! He withdraws his hand, due to theft. (Either he thought that they are Hefker, or Nochrim are established to be robbers, and their land is not theirs. - PF)
