Adding a table leaf on Shabbat

Hi,

One may add a leaf to a table on Shabbat.

Although one may not create a roof over a space on Shabbat, this is acceptable 1) because one is adding to an existing "roof", 2) because the table is made for such expansion, and 3) because the primary problem is where there are both roof and walls, and our tables do not have walls.

(Rivivot Ephraim 1:222:3)

Have a great day,
Mordechai

Putting a plastic cover over a succah on Shabbos

Hi,

One may put a plastic cover atop a succah on Shabbos. This is not called "construction", because the cover is clearly temporary. Even putting such a cover atop a non-ritual hut would be permitted, because it's not something one leaves atop the hut.

The above assumes the plastic cover is directly atop the roof; one may not support it above the roof, for that would constitute the separate problem of constructing an independent roof (ohel).

(Rav Moshe Feinstein, Igrot Moshe Orach Chaim 5:39:4)

Have a great day,
Mordechai

Putting up window shades on Shabbat

Hi,

One should not leave window shades to be put up on Shabbat, due to the strain involved. However, should shades fall from their place on Shabbat, one would be allowed to put them back up. They are not considered muktzeh when they fall.


(Rav Moshe Feinstein, Igrot Moshe Orach Chaim 5:21:6)

[I am not sure why Rav Moshe does not discuss the potential problem of construction here. Perhaps, as appears likely from the wording of his responsum, he is discussing shades which are routinely attached and removed.]

Have a great day,
Mordechai

Extending the hood of a carriage on Shabbos

Hi,

One may extend the hood of a carriage on Shabbos, if one left it extended one tefach (3.6 inches) before Shabbos.

(Rav Moshe Feinstein, Igrot Moshe Orach Chaim 4:105:3)

Have a great day,
Mordechai

Hearing aids on Shabbat

Hi,

We are lenient regarding use of a hearing aid on Shabbat. This is different from use of a microphone:

With a microphone we are concerned that people normally connect it only when they need it, so that people will assume it was turned on during Shabbat, but that concern only applies regarding items which make noise, calling themselves to the attention of the public.

The concern of "don't use it lest you adjust it" which we express regarding microphones also applies regarding hearing aids, but a) that is a rabbinic decree and so it may not apply to the uncommon case of a hearing aid (for rabbinic decrees were created only for common cases), and b) the hearing aid involves great need, such as to hear an oncoming car. However, one should do something to prevent actual adjusting.

As far as the concern that one activates a microphone to create a new voice when he speaks, and so one is finishing its construction (makeh b'patish) or actually building it (boneh), neither of these is clear-cut, and this is a case of great need, as we have explained. [There is more here in Rav Moshe's discussion.]

As far as the concern that one's voice causes the electrical current to rise or fall, the prohibition involved is not clear, and this is a case of great need.

Further, sometimes the hearing aid does not pick up the sound, and so its activation is not a guaranteed result of one's action.

Further, if one speaks to people in general, and not only to the person with the hearing aid, then one does not intend to activate it. Indeed, ideally one should avoid speaking to him personally, if at all possible.

(Igrot Moshe Orach Chaim 4:85)

Have a great day,
Mordechai

Microphones on Shabbat

Hi,

There are four main reasons to prohibit speaking into a classic microphone on Shabbat:

Causing a microphone to broadcast a sound via its reaction to one's voice may involve completing the microphone's functionality or building it, which would be biblically prohibited;

Causing the electrical current to rise and fall may involve biblical prohibitions, even though the circuit remains "on" throughout the operation of the microphone;

We may not engage in activities which appear to be prohibited ("marit ayin"), and since microphones are normally turned on only when needed, listeners may not realize that this sound system was turned on before Shabbat;

If the sound system were to malfunction, one might forget it is Shabbat and adjust it.

(Rav Moshe Feinstein, Igrot Moshe Orach Chaim 4:84)

Have a great day,
Mordechai

Playing with Lego on Shabbat

Hi,

May one play with LEGO^TM or K'NEX^TM on Shabbat?

Two potential concerns arise regarding assembling parts into structures: boneh (construction) and metaken mana (improving an implement).

Halachic authorities offer two reasons for leniency in use of these toys:
• Neither strength nor craftsmanship is ever involved in attaching the pieces to each other, and we have halachic precedent to permit assembling usable entities from distinct parts, where neither strength nor craftsmanship is involved.
• The items created are not normally left intact for more than a few days; according to many authorities, even something which lasts for a week is not considered "permanent".

Based on these two reasons for leniency, authorities permit children to play with these toys, but some recommend against adults using them. Rav Moshe Feinstein prohibited blocks used in construction, even for children, but the type of toy involved is unclear.

(Rashi Beitzah 32b binyan arai; Pri Megadim 315:1; Mishneh Berurah 313:45; Yesodei Yeshurun 4:99; Igrot Moshe Orach Chaim 5:22:27; Be'er Moshe 6:25; Shemirat Shabbat k'Hilchatah 16: footenote 53; Tzitz Eliezer 13:30)

המצפה לישועה,
Mordechai

A succah constructed on Shabbat

Hi,

One may not use a succah which was constructed by Jews on Shabbat, even if no other succah is available.

(Rav Moshe Feinstein, Igrot Moshe Orach Chaim 4:69:5)

Have a great day,
Mordechai