Halacha for Monday 25 Tammuz 5781 July 5 2021

“Ketev Meriri”

The Midrash Shocher Tov on Tehillim states regarding the verse (Tehillim 91) “From the pestilence that walks in darkness”: “The Sages explain that this refers to a demon (a harmful being created on Erev Shabbat at the time the world was created and is neither fully spiritual like angels nor fully physical like human beings). Rav Huna said in the name of Rabbi Yose that the ‘Ketev Meriri’ demon is made of many peels, many hairs, and many eyes. It sees with one eye and this eye is within its heart. It has no power either in the sun or in the shade; rather, its power is between the sun and the shade. It rolls around like a ball and has power from the fourth hour of the day until the ninth. It has power from the Seventeenth of Tammuz until the Ninth of Av. Whoever sees it falls over and dies.” Similarly the Midrash Rabba on the verse “All of her enemies overtook her between the straits” explains that this refers to the three weeks between the Seventeenth of Tammuz and the Ninth of Av when “Ketev Meriri” is present. This means that our Sages, who were fluent in all of the secrets of the world, tell us that there is a harmful demon called “Ketev Meriri” present during this period of the “Three Weeks” and we must therefore conform our behavior and be aware of this fact during this period of time.

One must take care not to walk around alone during these three weeks beginning from the fourth hour of the day until the end of the ninth hour, which is a total of six hours. (The way to calculate these hours is from dawn, meaning that one must begin being careful from after three hours after dawn have passed for a duration of six hours. These hours are seasonal halachic hours, i.e. in Israel each halachic hour during this time of year is approximately and hour and a third. Thus, six halachic hours amount to approximately eight regular hours from approximately 8:15 am until 2:00 pm.)

The Aruch Ha’Shulchan points out that this prohibition only applies in a place where there are no people around at all, for instance, if one is walking through a forest and the like; however, within the city where people are present, it is permissible to walk around alone. (There are those who rule stringently even within the city, but the custom is not so.)

Similarly, one must take care not to perform any dangerous activities during the time “Ketev Meriri” is present. The Midrash and Poskim speak lengthily about this issue.

The Poskim write that one should not reveal the reasons of the Torah, such as these, in public; we are even warned not to reveal the reasons for the decrees of our Sages in public, for there may be ignoramuses who will mock ideas that seem foreign to them. We have nevertheless discussed the idea of the presence of “Ketev Meriri,” for this is a matter which may lead to danger and it is proper to warn the public about it.

Ask the Rabbi


ספר אביר הרועים - בית מידות
ספר אביר הרועים
לפרטים לחץ כאן

הלכה יומית מפי הראש"ל הגאון רבי יצחק יוסף שליט"א

דין ברכת שפטרנו מעונשו של זה
לחץ כאן לצפייה בשיעורים נוספים

Recent Halachot

"תנא דבי אליהו כל השונה הלכות בכל יום מובטח לו שהוא בן העולם הבא"

נדה ע"ג א'

8 Halachot Most Popular

The Laws of Mentioning “Mashiv Ha’Ruach”

We Begin Reciting “Mashiv Ha’Ruach” “Mashiv Ha’Ruach U’Morid Ha’Geshem” is a praise we recite to Hashem during the winter months within the “Mechayeh Ha’Metim” blessing of the Amidah as is printed in all Siddurim. We begin recitin......

Read Halacha

The Laws of One Who Forgets to Mention “Ve’Ten Tal U’Matar” in the “Blessing of the Years”

In the previous Halacha, we have discussed in a general manner that our Sages enacted that beginning from the Seventh of Marcheshvan (outside of Israel from the Fourth or Fifth of December), one begins reciting “Ve’Ten Tal U’Matar” (a request for dew and rain) in the “B......

Read Halacha

Eating and Washing One’s Self Yom Kippur

Some Laws of Yom Kippur All are obligated to fast on Yom Kippur, including pregnant and nursing women. Any woman whose health is at risk due to the fast should consult a prominent Torah scholar who is well-versed in these laws and he should render his ruling whether or not she must fast. One whose ......

Read Halacha

“The Blessing of the Years”

Beginning from last night, the Seventh of Marcheshvan, we have begun to request rain in the Amida prayer (only in the Land of Israel; the law for those outside of Israel will be discussed further). Let us therefore review some of these pertinent laws. The Enactment of the Sages to Request Rain O......

Read Halacha


The Laws of Shevi’it in a Cooperative Garden

This year (5782) is the Shemitta year. In previous Halachot, we have already explained the basic laws of Shemitta including the fact that one may not plant in or work (in any manner) any land within the Land of Israel unless the work is meant to protect the crops from harm that will befall them if t......

Read Halacha

When the Sanctity of Shevi’it Will Apply to Fruits and Vegetables and More on “Heter Mechira”

In the previous Halachot we have explained that any produce grown in Jewish-owned fields in the Land of Israel this year (5782) retain the sanctity of Shevi’it. We have likewise discussed the ramifications of this sanctity and the proper way to treat such produce. This sanctity rests even on f......

Read Halacha

Sprouting Avocado Pits During Shevi’it and the Blessing on Hydroponic Produce

Question: What is the blessing on vegetables that grow from the water (and not from the ground)? Likewise, is it permissible to plant such hydroponic produce during Shevi’it? Answer: The Blessing on Mushrooms and Truffles The Mishnah in Masechet Berachot (40b) states: “On things whi......

Read Halacha

Forbidden and Permissible Forms of Work During Shevi’it

In this Halacha and the next, we shall discuss the basic laws of tending to a garden during Shevi’it. We shall not discuss all of the details of these laws, for these laws do not apply to those residing outside of Israel. Works Forbidden by Torah Law and Rabbinic Enactment Some works forbi......

Read Halacha