Halacha for Wednesday 3 Shevat 5780 January 29 2020

Writing on a Window on Shabbat

Question: In the winter when it is cold outside and there is condensation or frost on the window, may one use one’s finger to write or draw on the window?

Answer: One of the thirty-nine works forbidden by Torah law on Shabbat is writing. Nevertheless, our Sages teach us that the Torah prohibition of writing on Shabbat only applies when one writes something lasting, such as when one writes with a pen on paper, for such writing is certainly meant to last for a long time.

Nonetheless, the Mishnah (Shabbat 104b) and the Rishonim explain that our Sages prohibited writing even through a method that is not meant to last, such as writing with berry juice on a table and the like.

Thus, it is forbidden to write using one’s finger on sand or ash on Shabbat. It is likewise forbidden to write on a substance which is not meant to last for a long time, such as writing on an onion peel, which the Tosefta (Shabbat, Chapter 12) states is forbidden on Shabbat. Although according to Torah law, writing on an onion peel on Shabbat is permissible since the onion peel cannot last for a long time (as it will soon dry out and shrivel up), nevertheless, our Sages forbade even such writing on Shabbat.

Based on the above, one of the greatest Acharonim, the Peri Megadim (Mishbetzot Zahav, Chapter 340, Subsection 3) writes that one may not write letters with one’s finger on glass windows in the winter when there is condensation or frost on the window as a result of differences of the indoor and outdoor temperatures. Nevertheless, merely drawing a straight line on a frosty window is permissible on Shabbat, for this is not included in the kind of writing our Sages forbade. Maran Rabbeinu Ovadia Yosef zt”l rules likewise in his Chazon Ovadia-Shabbat, Volume 5, page 148.

Based on the above we can derive that the same applies to drawing, such as drawing a face or any other figure or picture one deliberately draws on the frosty window or on the glass of a dirty car window and the like is completely forbidden on Shabbat, for this is likewise included in the writing forbidden by the rabbinic enactment on Shabbat.

Nevertheless, wiping one’s finger across a completely clean and dry table or in the air in order to signal something to one’s friend is permissible on Shabbat, for this is not considered writing at all.

Summary: One may not write or draw on a window which has frost or condensation on it as a result of the cold outside. It is likewise forbidden to write or draw on a dirty glass window and the like.

8 Halachot Most Popular

The Laws of Glassware and Pyrex Regarding the Prohibition of Milk and Meat Mixtures-Continued

In the previous Halacha we have written that according to Maran Ha’Shulchan Aruch, glassware does not absorb any flavor from foods placed in it and thus, there is no prohibition to use a glass vessel for meat and then after it is washed well, to use it for dairy (although the Rama does rule st......

Read Halacha

Question: Must one designate two different sets of glassware for dairy and meat as one would with other utensils?

Question: Must one designate two different sets of glassware for dairy and meat as one would with other utensils? Answer: We have already established in the previous Halacha that one is obligated to designate two separate sets of dishes and flatware for dairy and meat, for dishes used with either......

Read Halacha

The “Shehecheyanu” Blessing on a New Garment

Question: When is the appropriate time to recite the “Shehecheyanu” blessing on a new garment, at the time of purchase or the first time one wears it? Similarly, must one recite this blessing for every new piece of clothing one purchases? Answer: The Mishnah (Berachot 54a) teaches us ......

Read Halacha

The Laws of Milk and Meat Dishes and the Laws of Giving Putrid Taste

When one cooks meat in a pot, the walls of the pot absorb some of the food cooked in it and is therefore considered “meat”. If dairy is later cooked in the same pot, the pot will release some of the meat flavor contained in its walls into the dairy food and will therefore prohibit the en......

Read Halacha


Reciting the “Shehecheyanu” Blessing on Similar Types of Fruit

In the previous Halacha, we have established that one should recite the “Shehecheyanu” blessing on citrus fruits, such as grapefruits or oranges, which are not so readily available throughout the year. When one merits eating from these fruits the first time during the year and the fruits......

Read Halacha

Reciting the “Shehecheyanu” Blessing on Grafted Fruits

Question: May one recite the “Shehecheyanu” blessing the first time during the year one eats citrus fruits, such as grapefruits or oranges? Answer: We must first preface this discussion with the law that when one eats a new fruit that one has not yet partaken of that year, after recit......

Read Halacha

The Prohibition of Milk and Meat Mixtures

The Torah states three separate times (Shemot 23 and 34; Devarim 14): “You shall not cook a kid in its mother’s milk.” Our Sages (Chullin 114a) expounded that each of the times this prohibition is mentioned comes to teach us another law: The first time it is mentioned teaches us ab......

Read Halacha

The “Three Weeks”

The three-week period between the Seventeenth of Tammuz and the Ninth of Av is dubbed by our Sages “Between the Straits,” based on the verse (Eicha 1, 3), “All of her enemies overtook her between the straits.” Our Sages tell us that these three weeks between the Seventeenth o......

Read Halacha