Originally the there was an issur not to move kelim on shaboss, now a keli shmelachto leheter can be used for any purpose, but what is considered a purpose?
שבת קכ”ד עמוד א
.מתני’: כל הכלים ניטלין לצורך ושלא לצורך. רבי נחמיה אומר: אין ניטלין אלא לצורך
גמ’: מאי “לצורך” ומאי “לא לצורך”? אלא אמר רבא: “לצורך” דבר שמלאכתו להיתר, בין לצורך גופו בין לצורך מקומו. “שלא לצורך” ואפילו מחמה לצל. ודבר שמלאכתו לאיסור, לצורך .גופו ולצורך מקומו אין, מחמה לצל לא. ואתא רבי נחמיה למימר: ואפילו דבר שמלאכתו להיתר, לצורך גופו ולצורך מקומו אין, מחמה לצל לא
The Ran explains that although according to Rava (which is the opinion that we follow according to halacha) one is allowed to move a keli shmelachto leheter even in a situation where he is doing it for the purpose of it not getting ruined i.e. mechamo letzsel, however, if one wants to move it for no purpose at all, it would not be permitted. The reason for this based on the previous Gemara we saw:
תנו רבנן: בראשונה היו אומרים שלשה כלים ניטלין בשבת: מקצוע של דבילה, וזוהמא ליסטרון של קדרה, וסכין קטנה שעל גבי שלחן. התירו, וחזרו והתירו, וחזרו והתירו, עד שאמרו: כל הכלים ניטלין בשבת, חוץ מן מסר הגדול ויתד של מחרישה … אלא אמר רבא: התירו דבר שמלאכתו להיתר בין לצורך גופו ובין לצורך מקומו, וחזרו והתירו מחמה לצל. וחזרו והתירו דבר שמלאכתו לאיסור, לצורך גופו ולצורך מקומו אין, מחמה לצל לא. (קכג:)
The Ran explains that, as we see from this Gemara, originally everything was forbidden to move, with time Chazal allowed people to move utensils in more ways until one was allowed to move any keli shmelachto leheter for any purpose, but that is only if there is a purpose if it is for no purpose at all one not is allowed to move it, for that is still included in the original decree of Nechemiah.
The Shulchan Aruch (308:4) paskens like the Ran, but explains this does not include food or seforim as these were never part of the original issur muktzeh and is therefore permitted even to move for no purpose.
The Mishna Berurah adds that plates, bowels, knives and cups are permitted to move for no purpose, as they too were never part of the original issur muktzeh (as Tosfos writes in our sugya). The MB adds that there are some who are machmir not to move even plates if it is for no purpose.
What classifies as no purpose? It is hard to categorize it, the Aruch Hashulchan (308:15) writes that as long as he is moving it for his enjoyment then it is considered to be for a purpose. If he is moving the item as misasek, meaning he does it mindlessly, then that would be considered for no purpose and would not be permitted.
The sefer Minchas Shabbos, which was an immensely popular sefer before World War II, concludes (Siman 88) as well, that one should be stringent in this matter. Being that he was a Chortkover Chosid (the sefer is adorned by many haskomehs of the Rebbes of Ruzhin including many of the descendants who at the time of writing the haskomehs were young boys who were not yet married) he asks the following question: He had witnessed many times how Reb Dovid Moshe of Chortkov would move his tabek pushkeh (snuff box) when he was bdviekus in a way that seemingly was for no purpose. How could he have done something like that if according to Halacha it is assur?
Some have suggested that as the tabek pushkeh was probably full with snuff, then it would be categorized as food, in which case the Shulchan Oruch writes one is allowed to move it for no purpose. As many poskim (Rav Wosner, Rav Elyashiv) agree that snuff can be classified as food in regards to muktseh, it would never have been part of the issur muktseh and would be permitted to move for no purpose even if it is in a box. Rav Shlome Zalmen writes (Shulchan Shlome 308:44) that it would be hard to find a case where one can say it is for no purpose, and in this case where the Chortkover Rebbe was banging with the tabek puskeh, if he wanted to do that action, then it would be considered for a purpose.
The Minchas Shabbos answers that it is known the Chortkover Rebbe does not raise his hand if it is not for heavenly purpose. Being that is the case, although it may seem to us that he was moving the tabek puskeh mindlessly, in reality the movement was in order for him to be meyached some yechud and was for some higher purpose.
In the back of the sefer the Minchas Shabbos writes that some Godol (believed to have been the Binyan Shlome from Vilna) asked him from the last passage in Mesechtes Shabbos:
עולא איקלע לבי ריש גלותא חזייה לרבה בר רב הונא דיתיב באוונא דמיא וקא משח ליה אמר ליה אימר דאמרי רבנן מדידה דמצוה דלאו מצוה מי אמור אמר ליה מתעסק בעלמא אנא (קנז.)
Ulla happened to come to the house of the Exilarch. He saw Rabba bar Rav Huna sitting in a tub of water and measuring it. He said to Rabba bar Rav Huna: Say that the Sages said that it is permitted to measure on Shabbat only a measurement for a mitzvah. However, with regard to a measurement like this one, which is not for a mitzvah, did they say that it is permitted? Rabba bar Rav Huna said to him: I am merely acting unawares and am not at all interested in the measurements. Therefore, it is not prohibited.
Rabba Bar Rav Huna explained himself that he was not measuring anything in the bathhouse, rather he was acting mindlessly when he was measuring. If Rabba Bar Rav Huna could have acted misasek, doing something for no reason, then how can we say that the Chortkover Rebbe was greater than an Amora and never did anything without there being an heavenly purpose.? This was the question of the Godol to the Minchas Shabbos.
It is said that the Pnei Menachem answered that obviously as all great Rebbes, Rabba Bar Rav Huna would not have said the truth about himself, and admit that every movement was done for a heavenly purpose, but in reality that was the case.
The Minchas Shabbos writes that a Chosid explained a simple answer, as Rabba Bar Rav Huna was sitting in the bathhouse at that point, he was not able to have any heavenly thoughts or be meyached yechudim. Since one is not allowed to do and even think the words lesheim mitzvah (see MB siman 588 in BH) or any holy thoughts in the bathhouse, Rabba Bar Rav Huna was able to say he moved as misasek. The Chortkover Rebbe, on the other hand, was sitting at the Shabbos table and was able to have heavenly thoughts and be meyached yechudim, we can therefore assume that the movement of the tabek pushke was done for some higher purpose.