By Rabbi Dovid Ostroff
If a rock or a piece of glass pose as a hazard to the public, what may be done to remove it?
Any object that poses a threat to the public may be moved out of harm’s way.1 This is because handling muktze is a rabbinical prohibition and where public health is at stake, Chazal waved aside their restriction. Accordingly, if there is an open pit or manhole in the street one may cover it up, even if it involves handling muktze. Also, if a rock or piece of metal is lying in the road in such a way that they are likely to cause harm, if there is an eiruv or it is in a carmelis, 2 they may be carried to the side; if they are in a reshus harabim, 3 they may be moved less than four amos – put down 4- less than four amos – put down etc. until moved out of harm’s way.
We find though that if a rock is easily noticed and thereby the chance of it causing harm is remote, it may not be moved out of the way – in the normal manner, rather one should move it out of the way with one’s foot or any other abnormal manner. 5
I would like to crack open a nut with a rock on Shabbos, may I?
This and the following questions deal with the setting aside of objects which are not a k’li. Sticks and stones are categorized as muktze machmas gufo, which is a severe muktze in a way that it may not be moved even l’tsorech gufo um’komo – for example, to use a stone as a doorstopper.
However, their status can be altered. If one were to either: 6
Set the item aside before Shabbos for permanent use. This can be done either verbally or mentally.
Use it on a regular basis during the week, even without having mentally set it aside for permanent use.
Physically modify the item. In such a case it will be sufficient to set it aside even for one Shabbos.
In the above cases a stone or a stick may be used and handled on Shabbos.
As we see, setting aside an item for one Shabbos only is insufficient. However, there is an opinion that holds that setting aside for one Shabbos items regularly used for specific purposes is sufficient. Accordingly, where it is common to use a stone for a nutcracker, it would suffice to prepare it before Shabbos as such.
The Mishna Berura 7 rules that when necessary one may rely on this opinion. Seeing that in developed regions a manufactured nutcracker is used and not stones, if one wished to use a stone as a nutcracker, he would be required to adhere to one of the three points mentioned previously.
What about the using of a rock as a doorstopper?
The same rule applies to the using of a rock or brick as a doorstopper. In today’s specialized world a rock is not commonly used as such. Therefore, if one would like to use a rock as a doorstopper, it would be preferable to adhere to one of the above three points.
When walking in the forest, may I plop down onto any stone?
Obviously, the stones in the forest were not prepared by you to be used as benches. Therefore, you may not move them around in order to make them comfortable for sitting on. However, sitting on them does not require you to physically handle them, and therefore you may sit on them, 8 even though they might move when sat upon. This is permitted because it is called tiltul b’gufo – handling muktze through one’s body and not with one’s hands.
 Simon 308:18.
 A public domain, where the prohibition of carrying is only a rabbinical one.
 A public domain, where carrying is forbidden from the Torah.
 Standing still is equivalent to putting it down. M”B simon 266:18.
 M”B 308:75. See also the Bi’ur Halacha “kotz”.
 Simon 308:21-22.
 Simon 308:97.
 M”B 308:82,88. In M”B 82 he brings a Me’iri which says (in a case when the rock will move when sat upon) that if not necessary, it is preferable to abstain from it. However, in simon 308:13 the M”B did not mention this clause. The solution may be that sitting on muktze is using it, which is more severe than the plain moving of muktze.