1) "ARSA D'GADA" -- THE "GOOD LUCK BED"
QUESTION: The Beraisa describes which beds must be overturned in the house of the Avel. The Beraisa says that a "Dargash" does not have to be overturned, but it should be stood up on its side. Raban Shimon ben Gamliel says that the Dargash's support straps should be loosened and the Dargash allowed to fall by itself.
Ula explains that a Dargash is an "Arsa d'Gada" -- a special bed designated exclusively for bringing good fortune into the home, upon which no one sits or sleeps, as RASHI here (DH Arsa d'Gada) explains. RASHI in Sanhedrin (20a) adds that it brings good fortune through "Nichush," superstition.
Why is one permitted to set up a bed in one's home for the purpose of Nichush? The Torah explicitly prohibits Nichush (Vayikra 19:26)! Moreover, when the RAN in Nedarim explains the meaning of the word "Gada" ("Gad," or "Mazal"), he cites the Gemara in Shabbos (67b) which says that a person who attempts to improve his luck by saying, "Let my Mazal ('Gad') become fortuitous," transgresses the prohibition against Nichush. Rebbi Yehudah there adds that "Gad" refers to a type of idolatry, as he proves from a verse in Yeshayah (65:11). (CHIDUSHEI HA'RAN, Sanhedrin 20a)
(a) The ROSH in Nedarim (56a) explains that the Sar of Ashirus, the Divinely-appointed spiritual being in charge of wealth and success, is named "Nakid," or "refined" (Pesachim 111b, Chulin 105b). A person attracts that Sar to his home by maintaining a clean and neat home. For this reason, many people had the custom to beckon the Sar of Ashirus to visit them by keeping one bed in the home always neatly spread.
The EINAYIM LA'MISHPAT in Nedarim explains that the Rosh echoes the words of the SEFER CHASIDIM (#458): an act which works through supernatural means (Mazal, or Ru'ach ha'Tum'ah) is permitted if it is widely known that such an act brings about a certain result. Since that act has been tried and tested and found to be effective, relying on that act to obtain a certain result is not considered Nichush. This explains why the Chachamim caution against eating food left under a bed because of the Ru'ach ha'Tum'ah that resides there. Similarly, it is well-known that a home with a bed kept neatly spread enjoys success, and, therefore, it is not considered Nichush. (See Shabbos 67a, where the Gemara says that any act known to heal is not called Nichush; see also Insights to Shabbos 67:2:c.)
It is possible that this is the intention of Rashi here as well. The purpose of the Arsa d'Gada bed is for a type of Nichush which is permitted (Rashi in Sanhedrin calls it "Nichush" only because it works through supernatural ways).
(b) The SHITAH MEKUBETZES in Nedarim writes that the Arsa d'Gada bed is not actually spread for good luck, but rather it is intended to welcome the heavenly emissary that Hash-m sends to bring wealth to a home. By honoring the emissary, one honors the One who sent him. Hence, the bed is unrelated to Nichush.
The Shitah Mekubetzes compares the Arsa d'Gada bed to the Kisei Shel Eliyahu set up at every Bris Milah to honor Eliyahu ha'Navi, the visiting emissary of Hash-m. (According to this explanation, it appears that it was only a Jewish practice to spread such an "emissary bed." It demonstrated a family's trust and confidence in Hash-m that He will send His Divine emissary to bring bountiful blessing to the home.)
(c) The RAN in Sanhedrin (20a) answers that the Arsa d'Gada was not made for Mazal at all. Rather, it was a form of expression of gratitude to Hash-m. By spreading a bed which is not even used, one shows that he recognizes that Hash-m has blessed him with more than he needs. The word "Gada" ("Mazal") in this context is a borrowed term. (Through thanking Hash-m for what He has given in the past, one merits to have more blessing in the home, and thus such a bed indeed brings wealth.)
2) MUST A MOURNER OR SICK PERSON STAND FOR A "NASI"?
OPINIONS: The Gemara quotes Rebbi Yochanan who says that everyone must rise for a Nasi, except an Avel and a Choleh. Rebbi Yochanan adds that everyone is told to be seated, except an Avel and a Choleh. What is the reasoning behind these Halachos?
(a) Two reasons are suggested for why an Avel and a Choleh do not have to stand for a Nasi.
1. The simple reason is because they are weak and dejected, and for them to stand involves considerable discomfort. Although the Torah requires that one stand in honor of a Nasi, it does not require that one undergo excessive duress in order to do so.
According to this understanding, if the Avel or Choleh wants to stand for the Nasi, he may do so and he fulfills the Mitzvah.
2. REBBI AKIVA EIGER (to Shulchan Aruch YD 376) suggests a different reason for why the Mitzvah to stand for a Nasi does not apply to an Avel and a Choleh. The Gemara in Kidushin (31a) teaches that the Mitzvah to stand for a Nasi requires that one stand in a way which shows respect, a "Kimah she'Yesh Bah Hidur." There is no display of respect when an Avel or Choleh stands for someone.
According to this reasoning, even if the Avel or Choleh wants to conduct himself stringently and stand for the Nasi, he should not stand because his act of standing is not a fulfillment of the Mitzvah.
(b) The Rishonim suggest two explanations for why an Avel and a Choleh are not told to be seated.
1. Most Rishonim (RASHI, TOSFOS, and others) explain that Rebbi Yochanan refers to the Halachah he mentioned previously, that an Avel and a Choleh do not have to stand for a Nasi. Rebbi Yochanan teaches that if they do stand, they may be seated when they want and do not have to wait to be told to be seated. The Gemara in Horayos (13b) rules that when one stands for a Nasi, he must remain standing until the Nasi tells him to be seated. The requirement to wait for permission to sit does not apply to an Avel and Choleh. An Avel and a Choleh do not have to wait until they are told to be seated, because they were not obligated to stand up in the first place.
(The CHIDUSHEI HA'RAN cites a variant text of the Gemara which is the opposite of the Girsa in our texts. The Girsa he cites says that "we do not tell anyone to sit down except an Avel and a Choleh." Nevertheless, the intent of this Girsa is the same as the intent of the Girsa in our texts: when the people stand for a Nasi, we may not tell them to sit; they must wait until the Nasi tells them to sit. In contrast, we may tell an Avel and a Choleh to sit if they want to sit; they do not have to wait for the Nasi to give them permission to sit.)
2. The RAMBAM has an entirely different understanding of Rebbi Yochanan's ruling. He explains that the second statement of Rebbi Yochanan is unrelated to the first statement. Rebbi Yochanan's second statement means that anytime an Avel or Choleh is standing we do not tell him to "sit." The word "Shev" ("sit") might be misinterpreted to mean "sit down in your Aveilus" or "sit down in your illness" and implies that we are telling him to return to his state of mourning or illness.