When to Let Blood

Samuel said: [Aramaic] The interval for blood[letting]: [Hebrew] every thirty days; in middle age one should decrease [this frequency]; at advanced age one should once again decrease [the frequency].

Samuel also said: [Aramaic] The correct time for bloodletting: on a first day of the week, [on] a fourth [day], and on the eve of Shabbat, but not on the second or fifth [day].

Because the master said: [Hebrew] He who possesses the merit of the fathers may let blood on the second and fifth [day], because the [heavenly] court above and the [human court] below are equal [in their working].¹

[Aramaic] What is the reason for not [doing it] on the third [day] of the week? [This is] because the planet Mars [lit., the reddening one] rules at even-numbered hours [of the day].

But on the eve of the Sabbath, it rules at even-numbered hours, too! Since the majority of people have become indifferent to it, [we trust in the verse] the Lord preserves the simple ones (Psalm 116:6).

[Aramaic] Samuel said: A fourth [day of the week] that is the fourth [day of the month], a fourth [day of the week] that is the fourteenth [day of the month], a fourth [day of the week] that is the twenty-fourth [day of the month], [and] a fourth [day of the week] that is not followed by four [days until the end of the month]—[all these constitute] danger.

The first day of the month and the second [cause] weakness; the third [day of a month constitutes] danger. The eve of a festival [causes] weakness; the eve of the festival of Shavuot [constitutes] danger. And the rabbis decreed [a prohibition of bloodletting] upon the eve of every festival because of [the danger that manifests on] the eve of the festival of Shavuot.

On [Shavuot] a demon called “slaughtering” goes out. And had not Israel accepted the Torah [on that very day], it would have slaughtered their flesh and blood.