Melacha #21: KOSHEIR - TYING

Av Melacha: Making a permanent knot (in a thread of a woven cloth).

Principle: Permanently fastening two ends together [without using a third item].

Toldah: Plying rope or twisting fibers of string together to form a new, stronger string.

One should, therefore, not twist the entwined ends of Tzitzit to keep them together. (There are differing opinions regarding the use of wire twist ties used to close plastic bags.)

Tying permanent knots:

Rules:

1. An attachment is only called a knot if:

a. Both ends of the string pass through to the other side, and

b. The knot stays tightened (either by itself, or through some other means -- e.g. with a bow) and can't be easily undone.

For example, neither a bow, slipknot (by itself) or a loose knot is considered a knot. (Conversely, one is not allowed to tighten any existing permanent knot.)

2. A forbidden knot is defined by:

a. The type of knot -- i.e. whether it is a professional knot, and

b. What length of time the knot is to remain fastened.

Resulting Halachot:

A. Prohibited knots which are Chayav:

Any knot that is intended (by the person tying it or generally) to remain tied for more than one month ("permanent").

B. Prohibited knots which are Patur aval Assur:

1. Single knot with a bow that is intended (by the person tying it or generally) to remain tied for more than 24 hours (and less than one month).

2. Double knot using two ends (e.g. a square knot) or single knot in one end (e.g. an overhand knot), that is intended (by the person tying it or generally) to remain tied for any definite length of time.

3. Any other "professional knot" (e.g. sailor's knots) that is intended (by the person tying it or generally) to remain tied for any length of time.

C. Knots permitted only for a mitzvah (e.g. tying the belt around a Sefer Torah on Shabbat), or in time of great need:

Any knot that is intended (by the person tying it as well as generally) to remain tied for less than one week. Examples:

1. Single knot with a bow.

2. Double knot using two strings (e.g. a square knot).

3. Single knot in one end (overhand knot).

D. Permitted knot:

A single knot with a bow (e.g. shoelace or necktie), if intended (by the person tying it as well as generally) to remain tied for less than 24 hours.

Melacha #22: MATIR - UNTYING

Av Melacha: Untying a permanent knot in order to repair it or to tie it differently.

Principle: Untying two articles that were permanently fastened to each other, for a constructive purpose.

Toldot: Untying a permanent knot, or cutting a string with a permanent knot, in order to tie a new one.

Rules: 1. Any accidentally-tied knot (whether tied on Shabbat or beforehand) may be untied on Shabbat, because it was never considered a "knot."

2. All knots which are permitted to be tied on Shabbat are permitted to be untied, and all knots which are prohibited to be tied are prohibited to be untied.

One could be lenient and untie any knot (e.g. a double knot intended to last for less than a week) in cases of great pain or great discomfort -- e.g. untying a scarf or belt tied with a double knot.

3. Cutting a knotted string is equivalent to untying that knot. One may only cut such a string (even with a pair of scissors or knife) if:

a. It was permitted to untie that knot in the first place, and

b. The string or knot is not cut in the presence of people who are unfamiliar with these laws of Shabbat.