The two loaves of bread on Shabbat reminds us of the double portion of mun we received in the desert. Even though one portion would have been eaten by Shabbat morning, we still use two loaves in the morning and two for se'uda shlishit as a reminder of the miracle.

As on Shabbat, on Jewish festivals you should place a white cover above and another below the challot to remind us of the layers of dew and “mun” in the desert that the Israelites ate for 40 years.

On Shabbat (and Jewish festivals), you should place a white cover above the challot and another below (unless you have a white tablecloth).

Muktza (“set aside” in one's mind) is an item that normally has no permissible use (or no use) on Shabbat. Muktza items may not usually be moved by hand on Shabbat—even if your hand is gloved—except for certain Shabbat needs, such as you need the space or the item. However, it is ALWAYS OK to move muktza items with any other part of your body.
  Chazal instituted muktza rules to make Shabbat special by requiring that actions be done differently on Shabbat than on weekdays. The basis for the idea of muktza was when Moses/Moshe instructed the Children of Israel in the wilderness to prepare the mun for Shabbat in order to eat it on Shabbat. Chazal extended the idea to prohibit moving by hand on Shabbat anything that was not prepared in one's mind before sunset on Friday.
The several categories of muktza vary according to their purpose and their permissibility to be moved. Purpose Item whose normal purpose is forbidden to be done on Shabbat.
Permissibility To Be Moved You may move this item by hand, without using a shinu'i:

• If you need the space where it is resting, or
• For a permissible use.

• Using a hammer to open a coconut.
• Using pliers to crack open nuts.
• Using a portable radiator to prop open a window.

No prior preparation or thought before Shabbat is required.
Note You may not move it just to protect the item.

Muktza Machmat Gufo: No Use
Purpose An item that has no use. This item is not normally ever designated for use; for example, a rock or stone. However, an item in this “no use” category is rendered non-muktza and usable on Shabbat as long as you had intended--before Shabbat or the festival began--to use it for a permitted purpose. As long as you intended that, you do not even need to use a shinu'i. If you did not intend, before sunset on Friday, to use this normally unusable item, then you may only move it using a shinu'i.
Permissibility To Be Moved Unless you prepared before Shabbat to use it for some permitted purpose on Shabbat, you may not move it by hand even for a permitted use and not even in order to use the space where it is resting.
Note You might need to use the item regularly for the non-standard purpose because for just a one-time use, it might not be permitted. Consult a rabbi.
Exception Garbage has no use. You may move garbage within your house (example: push the garbage across the room with your foot), but if you want to dump your garbage outside and you have a private domain or an eruv, you may pick it up and carry it outside.

Muktza Machmat Chisaron Kis
Purpose A valuable item that you are concerned may be damaged.
Examples Passport, porcelain china, or other expensive and fragile or difficult-to-replace objects.
Such an item may not be moved except for its designated purpose and you may not move it once you have finished using it. But once you are already holding it, you may take it to a place where you want to leave it and you do not need to drop it where it is when you finish with it.  

Basis L'Davar Ha'Asur

Purpose Muktza item resting on a normally permitted item makes the lower item muktza too.
Example A candlestick will render the table on which it stands muktza (unless there are one or more other items that are more valuable than the muktza item, in which case the table does not become muktza).
Situation There are multiple objects; some are permitted and some are not—for example, in a drawer.
What To Do If the permissible objects are more valuable than the non-permitted objects, you may open the drawer.

Non-Muktza on Top of Muktza
If you want a non-muktza item that was left on top of a muktza item from before Shabbat started, you may use it without restriction.

 

Situation

You discover you have coins in non-patch pockets of your pants that you will wear on Shabbat.

What To Do

You may empty coins out of non-patch pockets if you need to use the pants, but not by taking the coins out: you must dump them out of the pockets.
Note If you have coins in a patch pocket, the whole garment is muktza, unless you forgot that the coins were there or if you intended to remove the coins before Shabbat began but forgot to remove them (in which case you may shake the coins out of the pocket and the garment is not muktza).

Non-Patch Pockets

Situations

Pants with muktza items in the pockets are on your bed and you want to sleep on Shabbat afternoon.

What To Do

You may move the pants off your bed using any body part including your hands; no shinu'i needed.

Item that Becomes Muktza
If you are holding a permissible item and it becomes muktza, you may put it in safe place; you do not need to immediately drop it or put it down where you are.
Example You are holding a pot from which you dispense all of the food. The empty pot is now muktza, but you may take it to the kitchen to put it down.

For More Information about Muktza

To see the TorahTots article on muktza, click here.