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Weekly Shabbos Halacha Series
Halachos Series on Hilchos Shabbos

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Published by
Pirchei Shoshanim

A Project of
The Shema Yisrael Torah Network

Written by

Rabbi Dovid
Ostroff, shlita


These Halachos were shown by Rabbi Ostroff to
HaGaon HaRav Moshe Sternbuch, shlita



Questions for the Week of Parshas Toldos


With your permission, we will take a break from hilchos brachos for a while and return to hilchos Shabbos.

Am I permitted to insert a new shoelace into a shoe on Shabbos?

One could easily think that there is nothing wrong with inserting a shoelace into a shoe, being that it does not involve craftsmanship or cutting or any other melacha. Nevertheless Chazal tell us that it involves   making a kli.

We find the gemora Shabbos 48a saying that one is permitted to reinsert feathers into a pillow they were previously in but not to introduce them into a pillow for the first time. The reason behind this is because the relationship between the feathers and the pillowcase form a kli. The same applies to the shoe:

The shoelace complements the shoe and makes it functional; therefore threading the lace into the shoe is . [1]

Does this only apply to new shoes and new laces?

This halacha applies equally to old shoes, new ones, old laces and new ones. In other words one may not replace a torn shoelace with a new lace or with an old one, regardless of whether the shoe is a new one or an old one. The logic of   equally applies, because with all these cases a lace and a shoe form a kli.

Am I permitted to swap shoelaces, i.e. to transfer shoelace from shoe A and insert it in shoe B?

No, you may not, for the same reason. Even though both shoes are functional but by introducing lace A into shoe B you are again making a kli. If a shoelace came out you may rethread it into the same shoe because the shoe and the lace have already formed the kli.

Is this halacha applicable in other areas as well?

Inflating a soccer ball for the first time invokes the same prohibition. This is because a soccer ball is inflated once and introducing air into the ball forms a kli. This is only true for items that are inflated and are not deflated subsequent to use. A rubber duck, for example, is not subject to this prohibition because it is inflated prior to use and deflated after use. This last halacha is based on the Magen Avraham (317:7) who says that one may thread a belt into trousers on Shabbos because the belt is removed after wearing.

Accordingly it is permitted to thread a wrong color shoelace (for lack of a more suitable one) for the first time on Shabbos because it will be removed after wearing. [2]

Likewise if the shoelace would be thread in such a way that one would not leave it as it is, it is permitted.

The idea behind this is that when the two items are permanently united we say that a kli has formed but when they are not permanent, we say that one item is merely aiding the other and the two together do not form a kli. [3]

If the cord in my pajama trousers came out, am I permitted to restring it on Shabbos?

According to the Mechaber one may restring a shoelace, a sandal strap a hood lace provided that he does not tie a knot in the string. [4] He bases his ruling on the Rambam.

The Mishna Berura [5] and many other poskim base themselves on the Tosefos and the Rosh who hold that one may rethread when two conditions are complied with:

1)     The thread is easy to thread. 2) One does not usually tie a knot subsequent to such a threading.

Accordingly each threading or stringing must be judged individually.

Lacing the hood is rather arduous and would therefore be forbidden to lace on Shabbos. The same can be said of the pajama trousers. Accordingly, even though one is merely restringing the item and as such making a kli would not apply, since it is difficult to restring it, it is forbidden to do so. [6]

Likewise, if subsequent to stringing one usually ties a knot to prevent it from slipping out, it is forbidden to insert the string or lace.

Is one permitted to remove the paper stuck to a Band-Aid on Shabbos? [7]

First, you may ask, since all the melachos of Shabbos are learned from the Mishkan, where did sticking or gluing take place in the Mishkan? The answer is that   sewing is one of the 39 melachos of Shabbos and Chazal tell us that since sticking is similar to sewing, it is ascribed a place of honor as a toladah (derivative) of Tofer. [8]

The Biur Halacha [9] explains that sticking is similar to sewing in the sense that both involve the joining of two items to each other and making them one.

Once sticking has been established, let us consider separating or tearing.

The reverse melacha of Tofer is tearing. Just as Tofer binds two items,  or tearing severs the connection between two items. [10]

Tearing or separating two pieces of paper or two pieces of leather stuck together involves the melacha of tearing. (Tearing these items apart in a destructive manner is not a biblical prohibition, only a rabbinical one, but that is not our current subject).

[1] MB siman 317:18.

[2] SSK 15:60.

[3] See the sefer Binyan Shabbos pages 158-159.

[4] Shulchan Aruch siman 317:2.

[5] MB 317:20

[6] The Shulchan Aruch HaRav explains that when something is hard to restring it is similar to Makeh Bpatish stringing it for the first time.

[7] With respect to these halachos it is necessary to declare that the poskim vastly differ in psak on almost every issue. We will present mainly only one school of thought Rav Shlomo Zalman Auerbachs ztzl. As to the practical side one must refer to ones rav.

[8] Rambam chapter 10, Shulchan Aruch simon 340:14. A toladah is also a biblical prohibition.

[9] Simon 340:14 " .

[10] Tearing obviously applies to the tearing of a single item into two, under certain circumstances, but it also applies to the separating of items sewn together.


Vort on the Parsha

Rivka told Yaakov to hide from his brothers anger and only return home after his anger subsides. The sum total of Yaakovs absence was 35 years. After 14 years in yeshiva, Elifaz was sent by Eisav to kill Yaakov, and after 20 years, Eisav came towards Yaakov with 400 army captains to annihilate Yaakov and his entire family. And that is after his anger subsided!

We can only imagine what his anger was like when he realized that Yaakov received the brachos.

So what prevented Eisav from killing Yaakov outright?

Kibud Av. His feeling for his father and not wanting to upset him, as he said , after my fathers demise I will kill Yaakov.

Anger control can be learned from Eisav.


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Note:  The purpose of this series is intended solely for the clarification of the topics discussed and not to render halachic decisions. It is intended to heighten everyone's awareness of important practical questions which do arise on this topic.  One must consult with a proper halachic authority in order to receive p'sak.