Is one permitted to cover a newly laid egg on Shabbos? What about placing a plate beneath it to catch it?

There is an often-quoted opinion in the gemora [1] that it is forbidden to move a permitted k’li for the sake of muktze. Accordingly one would not be permitted to cover a newly laid egg (which is muktze) on Shabbos. The halacha is not like this opinion, and therefore one may take a bowl or cup and cover an egg even though the egg is muktze.

However, because an egg is oval shaped and will move even when lightly touched, one must be extra careful not to touch the egg with the bowl when covering it. [2] If, on the other hand, the muktze item would not move when touched, it is not imperative that the bowl will not touch it. [3]

It is forbidden to place a plate beneath an egg that is muktze because of the prohibition of bitul k’li meheichano – rendering a k’li unusable on Shabbos. Since the egg is muktze it causes the k’li placed beneath it to be muktze as well, and one is forbidden to cause a k’li to become muktze on Shabbos. [4]

Under which muktze-status do you classify a wallet – with money and without?

Let us first define the status of money.

Money is classified as muktze machmas gufo, [5] which places it in the same category as sticks and stones, because it is not called a k’li. The rule applying to this category is that it is forbidden to move it even l'tzorech gufo um’komo – for the sake of using the actual coin or to use the space it is occupying.

A wallet/purse is called a k’li shem'lachto l’issur [6] – a k’li used for an issur, i.e. storing money. Therefore, if the wallet was empty when Shabbos began it has a status of a k’li shem'lachto l’issur and may be moved or handled l'tzorech gufo um’komo. Accordingly it may be removed from one’s trouser pocket in the regular manner. If the wallet contained money when Shabbos began, the wallet attains the identical status as the money due to the halacha of being a basis l’davar ha’assur –a base, a stand, for the muktze and becomes muktze machmas gufo. [7] In such a case it would be forbidden to remove the wallet from one’s trouser pocket in the regular manner and it would have to be tipped out.

Boneh

I had yet not removed the storm windows and a heat wave broke out on Shabbos. Am I permitted to remove them on Shabbos?

The Shulchan Aruch [8] teaches us that one is permitted to insert a board or screen into a window, even if the board is not connected or tied to the wall e.g. with a string. The purpose of the string would be to demonstrate that the board is not part of the building, but rather, it functions as a temporary plug and can be removed at random. The Mishna Berura [9] stipulates that this is only applicable when the board is regularly placed and removed from the window. Storm (double) windows are inserted into the window frame with the onset of winter and are removed at the beginning of spring or summer. This undeniably is not called frequent attaching and removal, and would therefore not be permitted on Shabbos. [10] See the footnote. If the windows are attached to the frame with hinges, unscrewing them or unhinging the windows would involve a Biblical prohibition of Soter – Dismantling.

As I opened the door to my room I realized that the door handle remained in my hand. Was I permitted to reattach it to the rod protruding from the door?

One of the central distinctions between Binyan B’keilim – the assembly of movable articles and Binyan B’karka – building construction, is that Binyan B’karka is applicable even through loosely attaching items to the building. This is because items attached to a structure become part of it even when loosely attached. Therefore, it is forbidden to reattach the handle to the rod/bar even loosely due to Boneh. The handle itself is muktze [11] and must be put down.

The same would apply to a filter attached to the faucet. If it became loose on Shabbos it is forbidden to tighten it, and if it detached from the faucet it is forbidden to reattach it even though one intends to attach it without force or skill.

As I was leafing through a calendar hanging from the wall, the nail that fastened it to the wall came out. Am I permitted to loosely reinsert it?

Based on the above, inserting a nail into a wall, even loosely, is akin to Boneh, and is forbidden. The same applies to a hook which detached itself from wall shelves or from a door. Also, if when closing or opening a curtain the rail partly-detached from the wall, it would be strictly forbidden to reinsert the rivet back into the wall.

I once saw the pin of a door hinge detach itself, and a tall fellow quickly reinserted it. I remarked that he was liable to bring a chatas – a sacrifice. He retorted that it was not a problem to reinsert it. Who was correct?

According to the above, reassembling or attaching anything to the ground or to fixtures attached to the ground is Boneh. Therefore, inserting a bolt into the hinge, even if it easily slips into place, would be the Melacha of Boneh, and the perpetrator of such an act on Shabbos would be obliged to bring a sacrifice.

If his intention was to reinsert it temporarily into the hinge until after Shabbos and remove it in order to repair it, there would be room to say that it would ‘only’ be an issur d’rabanan because it was not permanently attached.