Halacha for Sunday 13 Iyar 5781 April 25 2021

Tying Tzitzit Strings and Plastic Cable Ties on Shabbat

In the previous Halachot we have discussed some basic laws of tying and untying knots on Shabbat. The general rule is any knot that is either “professional,” i.e. requires some skill to make, or “permanent,” i.e. is meant to last for a prolonged amount of time, is forbidden to be made on Shabbat.

Tying an Additional Knot on Top of a Knot Which Existed Before the Onset of Shabbat
We have already mentioned that some authorities rule stringently and prohibit tying a double knot on Shabbat, for this is considered a professional knot. (For instance, when one ties one’s shoes, one usually makes one knot and another bow on top of that. Making another knot on top of the first one makes the knot stronger.)

Thus, the Poskim write that if there was one knot tied before Shabbat, one should not make an additional knot on top of it, for the second knot is the primary knot forbidden on Shabbat. This is similar to a situation where one letter was written before Shabbat and writes another letter on Shabbat thereby completing the word. For instance, if the letter “Alef” was already written and one then adds the letter “Bet” on Shabbat, it is considered that one has written the word “Av” (“father” in Hebrew), a word with a meaning, on Shabbat, which is a Torah prohibition. (It is a rabbinic prohibition to write even one letter on Shabbat.)

Similarly, if one adds another knot to a pre-existing knot on Shabbat, one transgresses the forbidden work of tying on Shabbat. Maran Rabbeinu Ovadia Yosef zt”l rules likewise in his Chazon Ovadia-Shabbat, Part 5, page 68. Although we have written previously that Maran zt”l rules that one who ties a double knot on Shabbat has on whom to rely, it is nevertheless worthy to act stringently regarding this matter.

Tightening Loosened Tzitzit
If one’s Tzitzit loosened on Shabbat, one may not tighten it on Shabbat, for this resembles tying a double not. This is especially true since there is room to say that tying Tzitzit is a kind of “professional” knot and Tzitzit are considered tied “permanently” since one never intends to untie them.

Plastic Cable Ties
The modern-day Poskim discuss whether or not one may use plastic cable ties on Shabbat. Should their use pose a concern of the forbidden works of tying or building on Shabbat? Maran zt”l rules (ibid. page 75) that there is no prohibition involved and one may use them on Shabbat, for this is not considered a “knot”; rather, the plastic cable is only caught and tightened. The Torah never discussed such a reality and our Sages never banned this kind of action, for this does not resemble the forbidden work of tying at all.

Summary: One may not tighten loosened Tzitzit strings on Shabbat. One may use plastic cable ties on Shabbat.

Ask the Rabbi


8 Halachot Most Popular

Taking Haircuts and Shaving During the Omer Period

Abstaining from Taking Haircuts During the Omer It has become customary among the Jewish nation to refrain from taking haircuts during the Omer counting period: According to the Ashkenazi custom, until the 33rd day of the Omer and according to the Sephardic custom, until the morning of the 34th day......

Read Halacha

Producing Sound and Whistling on Shabbat

The Gemara in Masechet Eruvin (104a) tells us that our Sages banned producing sound on Shabbat and Yom Tov, for instance, by playing a musical instrument, for they were concerned that while the tune is being played, the player will come to fix the instrument. This decree would certainly apply eve......

Read Halacha

Toys Which Produce Sound and those Which Operate Using a Spring or Coil

Question: Is it permissible for one to allow one’s young children to play with toys which produce sound, such as a doll which makes noise when shaken, on Shabbat? Answer: In the previous Halacha we have discussed the prohibition of producing sound on Shabbat, such as by banging on a board, ......

Read Halacha

Clapping and Drumming on a Table on Shabbat and Yom Tov

The Gemara in Masechet Beitzah (30a) states that one may not drum, clap, or dance on Shabbat lest one come to fix a musical instrument (ibid. 36b). This means that just as we have discussed in the previous Halachot that our Sages have decreed that one may not play musical instruments on Shabbat ......

Read Halacha


Praying in Pajamas

Question: Can one pray while wearing pajamas? Answer: Approximately one week ago, we have discussed that, before praying, one must prepare a fitting place, proper attire, and cleanse one’s body and thoughts, as the verse in the book of Amos states, “Prepare yourself before your G-d, I......

Read Halacha

Praying Barefoot

Question: May one pray while wearing sandals or while one is barefoot? Answer: When one prays, one must prepare one’s environment, clothing, body, and thoughts accordingly, for one will be standing before the King of all kings. Respectable Garments While Praying The Gemara (Shabbat 9b) ......

Read Halacha

Question: How many “Kezayit”s (olive’s volume) of Matzah must one consume during the Pesach Seder?

Answer: One is obligated to eat altogether three “Kezayit”s of Matzah during the Pesach Seder. Every Kezayit amounts to approx. 30 grams of Matzah. Nevertheless, there is room for stringency to eat four or even five “Kezayit”s of Matzah, as we shall now explain. The Order......

Read Halacha

Kissing One’s Parents’ Hands on Shabbat Night- The Students of Rabbi Shimon bar Yochai

Question: Should one kiss the hands of one’s parents and receive a blessing from them on Shabbat night and does the same apply equally to one’s father and mother? Answer: The Gemara in Masechet Avodah Zarah (17a) tells us that when Ulah (a sage who lived during the Talmudic era) would......

Read Halacha