sun and moon in Hebrew medical astrology

The relative importance of the sun and moon in determining dates bitterly divided Jews two thousand years ago.  The Qumran Jewish community that collected the Dead Sea Scrolls favored the sun.  Other Jews favored the moon.  The moon’s proponents prevailed.[1]  Today’s Jewish calendar is thus organized around lunar months, with adjustments made to preserve the position of lunar months within the solar year.

Medical astrology in an ancient Hebrew medical work suggests that disputes about the relative importance of the sun and moon endured for many centuries.  Hebrew medical astrology, like Galenic medical astrology, concerns primarily the medical significance of the lunar cycle.[2]  However, medical astrology in an ancient Hebrew medical encyclopedia called Asaph’s Book of Medicines largely ignores the moon.  Asaph’s Book of Medicines follows Hippocrates in directing attention to the seasons.[3]  It goes beyond Hippocrates to associate signs of the zodiac with months and to give medical prescriptions for each month of the year.  Asaph’s Book of Medicines, which appears to be a pseudo-epigraphical compilation written before 1200, seems to preserve implicitly a claim to the predominate importance of the sun compared to the moon.[4]

In lunar-solar orientation, most medieval Hebrew medical astrology differs strikingly from Asaph’s medical astrology.  David ben Yom Tov’s fourteenth-century Kelal Qatan is the “most detailed and extensive original Hebrew treatise on astrological medicine surviving in Hebrew literature.”[5]  In this work, and in an important tenth-century Hebrew source for it, the moon is the chief astrological indicator:

If you want to administer a foodstuff or potion in order to purge <the body of a patient>, do so when the Moon is in a sign similar to the humor which you want to expel.  For instance, if you want to expel yellow bile, do so when the Moon is in <one of> fiery signs, namely, Aries, Leo, and Sagittarius.  And black bile, when the Moon is in <one of> the earthy signs except for Capricorn, namely Taurus and Virgo.  If you want to expel phlegm, do so when the Moon is in <one of> the watery signs, namely Cancer, Scorpio and Pisces.  And if you want to expel blood, i.e., to perform bloodletting, do so when the moon is in one of the airy signs, namely, Gemini, Libra and Aquarius.[6]

Humoralism is ancient medical theory that Hippocrates is thought to have systematized.  It links health to the balance among four humors: yellow bile, black bile, phlegm, and blood.  Babylonian astronomers used signs of the zodiac by the middle of the first mellenium BGC.  Ptolemy’s Tetrabiblos in the second century GC helped to make signs of the zodiac a standard element in astrological reasoning.  To make medical prescriptions, Kelal Qatan combines these standard elements with the moon’s trajectory.

In contrast to Kelal Qatan, medical astrology in Asaph’s Book of Medicines combines humoralism and signs of the zodiac with the sun.  Medical astrology is only a small component of the latter work, but clearly recognizable within it:

The first month of the year in which falls the first holyday and the first season is Nissan.  Its sign is Aries; it is the first sign of the zodiac as is called Bahmin in Persian; this month is also the beginning of spring and the beginning of the periods, namely the Nissan period. …  This period is one quarter of the year and consists of three months.  It contains the following signs of the zodiac: Aries in Nissan, Taurus in Iyar, and Gemini in Sivan. …  The sages of Persia said the following: …when the plants begin to blossom and the sun is in the Aries constellation, namely in Nissan (called Bahmin Mah in Persian).  Then the physicians begin to administer various drugs and to give enemas in order to calm the body and let it rest; they prescribe the drug called Stomachikon or Akindinon in order to put out the flame of the red humor kindled by the heat of the blood. People governed by the black humor should not stop taking drugs in order to alleviate the power of the black humor and prevent illnesses. They should first drink a drug called pentaeidos, which is made from five ingredients: cuscusta epithymum, Polyporus officinale, Citrullus colocynthis, Aloe, and Convolvulus scammonia; all these ingredients  … . [7]

Asaph’s Book of Medicines contains traces of ancient Egyptian, Greek, Indian, Persian, and Syriac elements.  Within this work, a second version of the above text strips out the Persian references, eliminates the signs of the zodiac, and shifts the start of the year from that of the religious calendar (first month is Nissan) to that of the civil calendar (first month is Tishrei). But it retains humoralism, solar orientation, and similar medical prescriptions:

18) The seventh month is Nissan. The length of its days is thirteen hours and the length of its nights — eleven hours. In this month, the plants bud and blossom. People should beware not to eat the roots of vegetables which are plucked from the ground, because they are bad for people who eat them during all this month. People who eat them a lot during this month will be overcome by the phlegm and blood and will suffer from tonsillitis and other diseases.

19) People suffering from these disorders should drink the drug called Theodoritos the Great, once a week up to three times; this will cure them, with God’s help.

20) People governed by the black humor should take the following drug: seven shekels of Cuscuta epithymum, three shekels of Myrobalani cetrini, three skekels of Myrobalani bellerica …  Then, take one quarter of a shekel crushed Polyporus officinalis, one quarter of a shekel Convolvulus scammonia and add them to the above mentioned extract; all this should be heated on the fire and given to the patient early in the morning; this is the choice drug against the black humor.

21) If the patient is ill on account of the red humor, let him drink in this month Akindinon or Stomachicon, or Panditon (Pentiron) (one shekel); this will cure him, with God’s help. [8]

Asaph’s Book of Medicine includes such accounts for every month of the year.  Perhaps indicating the importance of astrology in this book’s sources, it refers several times to Asaph with an epithet derived from the Hebrew word for moon.  The epithet is thought to mean astronomer, astrologer, or medical astrologer.[9]  Asaph’s epithet thus roots the main tree of Hebrew medical astrology.

Despite that linguistic root, Asaph’s Book of Medicines scarcely considers the moon as an indicator for medical treatment.  The work considers recurring malarial fevers.  These fevers drove interest in analysis of critical days and lunar effects.[10]  Asaph’s book, however, considers without reference to the moon the treatment of recurring malarial fevers.  Lunar analysis linked to medicine appears only in brief remarks relating phases of the moon to attacks of madness.[11]  Asaph’s medical astrology is not rooted in lunar analysis.

Asaph’s solar orientation doesn’t merely reflect a longer time span of concern for illnesses and medicine. Consider Palladius’ commentary on a Hippocratic aphorism:

Hippocrates wished to inform us that the critical days follow the course of the moon, on account of the swiftness of the moon, just as prolonged illnesses follow the sun, on account of the sun’s slowness. So, just like the crises of prolonged illnesses occur with the changeovers of the four parts of the year, so also the crises in acute diseases occur in each quarter of the moon’s waxing and the completion of its illumination.[12]

Four quarters of the year correspond roughly to seasons.  Seasons are a recognized temporal concern in Hippocrates.  Months of the year are a different temporal unit that Hippocrates does not consider.  Moreover, Asaph’s book observes:

The course of all diseases is analogical to the daily course of the sun. The beginning of every disease is very hard, and so is the end of every disease. However, the middle of the period of disease is the worst, like the heat of the sun at noon. In the morning, it goes to the west but is not yet hot; in the evening, as the sun sets, its heat is burning; however, the heat of the sun at noon is worse than both. As the sun sets, its heat subsides. So is the course of diseases. In the beginning and end they are severe, but in the middle they are worse than both in the beginning and end. [13]

The daily movement of the sun describes a faster course than that of the moon.  Asaph’s preference for the sun doesn’t correspond to a perception of the sun’s slowness.  Asaph’s medical astrology seems generally oriented to the sun rather than to the moon.

Linking conceptually the Qumran community to Asaph’s Book of Medicines is plausible.  At least two expressions and two instances of unusual vocabulary connect the Qumran community’s Dead Sea Scrolls with Asaph’s Book of Medicines.[14]  Calendar diversity existed: some tenth-century Jews used a different lunar calendar than did other Jews.[15]  Diversity in primary sources as well as interpreters also existed: a Jewish Biblical canon did not emerge until after the destruction of the Second Temple in 70 GC.[16]  Moreover, Jews continued to use scripture written in Greek through to the sixteenth century.

Asaph’s Book of Medicines appears to be a rough compilation, preserving some ancient text aggregated with more recent text.  It seems to have been intended for practical medical use.  This unusual work apparently has been at the margins of Jewish intellectual life through later than 1200 GC.  Jews who persisted in asserting solar primacy long after the Qumran community had disappeared are plausible compilers for Asaph’s Book of Medicines.

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[1] Wise, Abegg, & Cook (2005) pp. 25, 379-85.  Id p. 384 observes:

Calendar wars can be vicious, and they are irresistibly divisive.  How can people compromise on whether today or two days from now is the Day of Atonement?  Easter may be this week or two weeks away, but one cannot split the difference and celebrate it next week.

Embrace of a particular, distinctive solar calendar unites the diverse Dead Sea Scrolls.  In addition to the Qumran community, a community of Jews just outside Alexandria 2000 years ago (the Therapeutae) also used a distinctive solar calendar.  So too did the Jewish authors of Jubilees and 1 Enoch.  See Taylor (2003) Ch. 7.

[2] Ben Yom Tov et al (2005) pp. 2, 18.  Galen, On Critical Days, Book III, concerns lunar medical astrology.  See Galenus, Hunayn & Cooper  (2011).  Ben Yom Tov et al (2005), pp. 2-15, provides a historical sketch of medical astrology and observes,  “Astrology was an interesting feature, but not at all prominent element, in the corpus of Hebrew and Judaeo-Arabic medical writing.” Id. p. 1.   Astrology appears to have been a highly valued element of ancient Islamic medicine.

[3] Hippocrates, Aphorisms, Section III, concerns the effects of seasons.  Asaph’s Book of Medicines contains a translation of Hippocrates’ Aphorisms.

[4] On Asaph’s Book of Medicines (Sefer Refuot), see Lieber (1984).  That study notes “the virtual absence of astrology in the work.”  Id. pp. 238, 247.  Scharback (2010), p. 117, in contrast, declares the work has “strong astrological associations.”  Cf. above.  The earliest indubitable reference to Asaph’s Book of Medicines is about 1200, while the oldest manuscripts probably date from the twelfth or early thirteenth century.  Id. 238.  The work itself places Asaph between Hippocrates and Dioscorides; if that’s a chronological ordering, then some of the text dates between the fifth century BGC and the first century GC.  A Mishnaic story refers to the suppression of a Book of Medicines by King Hezekia, a king of Judah reigning in the late eighth and early seventh centuries BGC.  Id. pp. 237, 233.  Muntner & Rosner (1971), which favors dating Asaph’s book to the sixth century GC, notes in its preface, “According to the manuscript in the British Museum, the Book of Asaph was re-edited by Donnolo (10th century) who also added new translations from original Greek sources.”  Asaph’s book doesn’t show any influence from well-developed ancient Islamic medical literature.  Plausible dating for Asaph’s book is from the sixth to the tenth centuries GC.  It’s probably the oldest surviving medical work written in Hebrew.

[5] Ben Yom Tov et al (2005) p. ix.  David ben Yom Tov, who is almost surely not the Portuguese Jew David ben Yom Tov ibn Bilia, probably lived in Provence or Catalonia.  He was either the father or son of the astronomer Jacob ben David Po’el ben Yom Tov Po’el (Bonjorn).  He wrote Kelal Qatan in the first half of the fourteenth century.  Id. p. 15.

[6] Id. p. 87 (source text para. 37).   The most important source for Kelal Qatan is Abraham Ibn Ezra’s twelfth-century The Book of Luminaries (Sefer ha-Me’orot).  It also has a lunar astrological orientation.

[7] Asaph’s Book of Medicines, trans. Muntner & Rosner (1971) pp. 34-6.  Red humor here is probably a mistranslation of Hippocrates’ yellow bile.   On the first month of the year being Nissan in the Jewish religious calendar, see Exodus 12:1-28.  While drift is a major issue for lunar calendars, the months of the Jewish calendar described in Asaph’s book apparently don’t drift through the solar year:

Summer begins on the twenty-fourth day of the month of Sivan, and lasts till the twenty-forth day of Elul. After the latter date, the day and the night are of equal length. Then, the night becomes longer at the expense of the day, until the twenty-fourth day of the month of Tevet. On this day, the night attains its full and is the longest of the whole year; the day of this date is the shortest.

Id. pp. 19-20.

[8] Id. pp. 105-7.

[9] Pines (1975) p. 251, n. 96.  Asaph, Asaph’s teaching colleague Yohanan ben Zabda (John son of Zebedee), and a Yehuda also mentioned in the text are all named with the epithet astronomer / astrologer.   In addition, Asaph is called “Asaph the Sage,” “Asaph the Physician,” “Asaph the Jew,” and “Asaph, son of Berechiah the astronomer.”  For the last, see Muntner & Rosner (1971) p. 194.

[10] Muntner & Rosner (1971) p. 29.  Langermann (2008) p. 99.

[11] According to Asaph’s Book of Medicines, “madness attacks the individual at fixed times, be it every full moon, or at the beginning of the month or at its end.”  Muntner & Rosner (1971) p. 15.  This lunar reference probably reflects folk wisdom, rather than astrological scholarship.

[12] Trans. Langermann (2008) p. 116.  Palladius was a sixth-century commenter on Hippocrates.

[13] Muntner & Rosner (1971) pp. 197-8.

[14] Pines (1975), p. 237 (Community Rule,1QS); p. 240 (the Damascas Document, 4Q266-272),  and Appendix IV (vocabulary).  One plausible, but not compelling, etymology derives Essene from an Aramaic word for “healers.” See Beall (1988) p. 36.  The account of the origin of medicine in Asaph’s book apparently comes from a Jubilees / Noahic tradition.  Jubilees texts occur relatively frequently among the Dead Sea Scrolls.  Jubilees uses a solar calendar.

[15] Abū Rayhān al-Bīrūnī’s The Remaining Signs of Past Centuries, written in 1000 GC, identifies the group as Maghrebi Jews and notes that their practice “stands in opposition to the custom of the majority of the Jews.”  See trans. Sachau (1879) p. 278.  Wise, Abegg, & Cook (2005) p. 383, which cites this reference, states that al-Bīrūnī called the Jewish sect the “cave dwellers.” I haven’t been able to find that in al-Bīrūnī’s text.

[16] Stone (2011) Ch. 5.


Beall, Todd S. 1988. Josephus’ description of the Essenes illustrated by the Dead Sea scrolls. Cambridge: Cambridge University Press.

Ben Yom Tov, David, Gerrit Bos, Charles Burnett, and Y. Tzvi Langermann. 2005. Hebrew medical astrology: David Ben Yom Tov, Kelal qaṭan : original Hebrew text, medieval Latin translation, modern English translation. Philadelphia: American Philosophical Society.

Bīrūnī, Abu-‘r-Raiḥān Muḥammad Ibn-Aḥmad al-, and Eduard Sachau. 1879. The chronology of ancient nations: an English version of the Arabic text of the Athâr-ul-bâkiya of Albîrûnî or Vestiges of the past. London: Allen.

Galenus, Claudius, Ḥunayn Ibn Isḥāq al-ʻIbādī, and Glen M. Cooper. 2011. Galen, De diebus decretoriis, from Greek into Arabic: a critical edition, with translation and commentary, of Ḥunayn Ibn Isḥāq, Kitāb ayyām al-buḥrān. Farnham: Ashgate.

Langermann, Y. Tzvi.  2008. “The Astral Connections of Critical Days.  Some Late Antique Sources Preserved in Hebrew and Arabic.” Pp. 99-117 in Akasoy, Anna, Charles Burnett, and Ronit Yoeli-Tlalim. 2008. Astro-Medicine: astrology and medicine, East and West. Firenze: SISMEL edizioni del Galluzzo.

Lieber, Elinor. 1984. “Asaf’s “Book of Medicines”: A Hebrew Encyclopedia of Greek and Jewish Medicine, Possibly Compiled in Byzantium on an Indian Model”. Dumbarton Oaks Papers. 38: 233-249.

Muntner, Sussman, and Fred Rosner, trans. & ed. 1971.  The Book of Medicine of Asaph the Physician: Commentary (vol. 1) and translated text (vol. 2).  Document 06-501-N-L, Prepared under the Special Foreign Currency Program of the U.S. National Library of Medicine and U.S. National Institutes of Health, Public Heath Service, U.S. Department of Health, Education, and Welfare, Located in: Modern Manuscripts Collection, History of Medicine Division, National Library of Medicine, Bethesda, MD; MS C 294.

Pines, Shlomo. 1975. The oath of Asaph the physician and Yoḥanan ben Zabda: its relation to the Hippocratic Oath and the Doctrina Duarum Viarum of the Didachē. Jerusalem: Israel Academy of Sciences and Humanities.

Scharbach, Rebecca  2010.  “The Rebirth of a Book: Noachic Writing in Medieval and Renaissance Europe.” Pp. 113-36 in Stone, Michael E., Aryeh Amihay, and Vered Hillel. 2010. Noah and his book(s). Atlanta: Society of Biblical Literature.

Stone, Michael E. 2011. Ancient Judaism: new visions and views. Grand Rapids, Mich: W.B. Eerdmans Pub. Co.

Taylor, Joan E. 2003. Jewish women philosophers of first-century Alexandria: Philo’s “Therapeutae” reconsidered. Oxford: Oxford University Press.

Wise, Michael Owen, Martin G. Abegg, and Edward M. Cook. 2005. The Dead Sea scrolls: a new translation. San Francisco: HarperSanFrancisco.

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