During the three-week mourning period between the 17th of Tammuz (the day the walls of Jerusalem were breached) and the ninth of Av (the day the First and Second Temples were destroyed), there is a custom to be careful to not to do anything that may be dangerous.1

While many are careful during the entire three-week mourning period, the custom is to be extra careful during the last nine days (from Rosh Chodesh Av through the ninth of Av).2

The reason for this is that it is an especially ominous time, as can be seen from the many tragedies that befell the Jewish people during this period, including the breaching of the walls around Jerusalem, the destruction of both Temples, the slaughter of the Jews of Beitar, and the Jewish expulsions from England, France and Spain (respectively). In more recent history, the Germans declared war on Russia on the ninth of Av 1914, precipitating the First World War, which had tragic repercussions for the Jews of Europe and ultimately led to the Second World War and the Holocaust. Till today, this time of year seems to be especially unpropitious.

In fact, the period of the Three Weeks is called Bein HaMetzarim (translated as “the narrow places” or “between the narrow straits”) after the verse in Lamentations, “Judah has gone into exile because of misery and harsh oppression; when she settled among the nations, she found no rest; all her pursuers overtook her in the narrow places.”3 The very name denotes a time of vulnerability.

Malicious Force

In addition to it being an ominous time, the Midrash describes a malevolent force named Ketev Meriri that is especially active during this three-week period.4 Rabbi Abba bar Kahana says that it is active from an hour before midday (the time when the sun is at the highest point) until midafternoon.5 Rabbi Levi places this activity somewhat earlier.6 We are further advised that this mysterious force does not walk in the sun or shade but in the shadow near the sun.

What to Avoid?

  • Try to avoid walking alone, especially from the end of the fourth halachic hour to the beginning of the ninth hour of the day.7 (Note: Most are of the opinion that this only applies to walking in the outskirts of a city, a place where people don’t frequent.)
  • Avoid excursions through dangerous areas, and avoid dangerous activities.8
  • Avoid hitting others, including students and children, even for disciplinary purposes.9 (Whether or not it is ever a good idea to do so is an entirely different topic and outside of the purview of this article.)
  • Unless it’s extremely urgent, one should try to avoid having surgery during the Three Weeks. If one is unable to delay it until after the Three Weeks, then one should try to schedule it prior to Shabbat Chazon (the Shabbat before the ninth of Av).10