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

Washing One’s Hands with Water from the Mediterranean Sea and Water Which has been Desalinated

Question: If one is at the beach and wishes to eat bread but has no water to wash one’s hands with, may one wash one’s hands using the water of the sea or ocean? Salty Water Answer: Regarding the laws of washing one’s hands for a bread meal, the Mishnah and Gemara teach us that......

Read Halacha

Immersing One’s Hands in Sea Water

We have explained in the previous Halacha that if one is on the beach and wishes to eat bread, one may not gather some sea water in a vessel and wash one’s hands, for sea water is salty and thus invalid for Netilat Yadayim. Immersing One’s Hands in a Spring, the Sea, or a Mikveh Howe......

Read Halacha

Washing One’s Hands in the Restroom

Question: Is it permissible to wash one’s hands (Netilat Yadayim) in the restroom or shower room? Answer: Maran Ha’Shulchan Aruch (Chapter 4) rules that one who exits the restroom requires Netilat Yadayim. Maran Ha’Chida writes that this is because of the evil spirit which rests......

Read Halacha

Listening to Music or Words of Torah in a Room Which Has a Bathtub or Shower in it

Question: May one recite holy words (words of Torah, prayer, or blessings) in a room with a bathtub or shower in it? Similarly, may one listen to holy songs or Torah lectures in such a room? Answer: There are two primary points which must be addressed: Firstly, whether or not one who is bathing a......

Read Halacha


The Eight Levels of Tzedakah

The Rambam (Chapter 10 of Hilchot Matenot Aniyim) writes that there are eight levels included in the Mitzvah of Tzedakah with each one being greater than the other. The highest level of Tzedakah is by helping to support a Jew who lacks his basic needs by providing him with money by means of a gif......

Read Halacha

The Mitzvah of Tzedakah and Donating a Tenth of One’s Earnings

By popular demand, we shall now discuss the topics of Tzedakah and donating a tenth of one’s earnings more broadly based on the words of Maran Ha’Shulchan Aruch and the Poskim and based on what is written in the works of Maran Rabbeinu Ovadia Yosef zt”l on this topic. Question: ......

Read Halacha

Food Items Touched by One Who Did Not Wash One’s Hands in the Morning

In the past, we have explained the obligation for one to wash one’s hands from a vessel every morning upon awakening from his sleep. We have also explained that when one awakens from one’s sleep in the morning, an evil spirit rests on one’s hands, for sleep is considered one-six......

Read Halacha

Question: Are those who customarily donate a tenth of their monthly income to Tzedakah permitted to deduct the cost of providing for their children still living at home from the sum of this ten percent?

Answer: We have previously discussed that one must donate a certain amount of Tzedakah annually. It is a “middle” level for one to give a tenth of one’s monthly profits every month. Now let us deal with our question regarding those who donate a tenth of their monthly profits to Tze......

Read Halacha