In the past few years a number of people who suffer from Celiac disease, a condition which results in “gluten-intolerance”, have been eating matzah made from Oats (Avena sativa) in order to fulfill their mitzvah of eating matzah on Passover. As is known from Mishnah Pesahim 2:5, only matzah made from one of the five grains can fulfill someone’s halakhic obligation. For those who suffer from Celiac disease eating matzah made from wheat is out of the question so matzah made from oats, although once thought problematic for Celiacs, have become a preferred option. The question which must be asked is are oats one of the five grains? As early as Rashi (Pesahim 35a) שיבולת שועל (“shibolet shual“) has been identified as oats (see Amar, 79-80 for other medieval sources). One of the first to express doubt as to this identification was Immanuel Low, the author of Die Flora der Juden, who identified shibolet shual as Sorghum vulgare, millet (Low, p. 738). More recently the late Yehuda Felix claimed that shibolet shual is to be identified with Hordeum distichum, two-rowed barley (see Felix 1985, 155 and 189). Felix’s supports his claim with the following evidence:
1. Oats were probably not domesticated in the Land of Israel during the Mishnaic and Rabbinic periods;
2. Shibolet shual and שעורין (“barley”) are considered as one species for the laws of kilayim (i.e. the prohibited mixing of certain plant species) and this is improbable is shibolet shual is oats since they are two very different species (see Mishnah Kilayim 1:1);
3. According to the Jerusalem Talmud (Hallah 1:1; 57b) shibolet shual is like a row (“כשורה”), something which is untrue with regard to oats.
Two of the most sustained critiques of Felix were by Yosef Efrati and Mordechai Kislev. Much of Efrati’s critique relies upon the מסורת, the traditional identification of shibolet shual with oats. While this tradition clearly existed, it was not necessarily correct. Kislev’s critique tries to argue with Felix through an examination of not only Jewish sources, but also through an examination of non-Jewish agricultural texts and botanical sources regarding the origins and dissemination of oats, both wild and domesticated. While Kislev clearly shows that oats were known in the ancient world, much if not all of these oats were wild and not domesticated until the middle ages, and then they were often grown, although not exclusively, for horses and not for people (see Zohary and Hopf, 77-82). Kislev’s critique and Felix’s response (Felix 1991) at times focused on botanical identification and classification, each believing that the sources supported their opinion. In the end I found much of Felix’s opinion more convincing. I found that even Kislev relied much upon the tradition, which is not to be ignored, of identifying shibolet shual with oats. Also, Kislev had to even redefine what we know as “bread” since any oat bread that could have been made in the Rabbinic period would have been very different from bread made from wheat, in no small part to the nature of oats, their high oil content which caused the oats to go rancid very quickly, and their difficulty in rising.
While both Felix and Kislev stress that they are intending just to bring the evidence into the public square, the discussion has been addressed by a number of poskim. Moshe Shternbauch in Teshuvot veHanhagot I:302 wrote that one who is gluten-intolerant is exempt from the obligation to eat matzah and since oats are not one of the five grains, eating oat matzah does not fulfill someone’s obligation. Shlomo Wassner, the author of Shevet haLevi, was asked about making matzot from oats and his concern is less with whether oats are shibolet shual than whether the process of making oat matzah is problematic. His ruling is that they are permitted (Shevet haLevi IX:117).
Much of this question relates to how one weighs a traditional interpretation or identification against possibly contradictory evidence. Does the tradition or custom always win out? Under what circumstances might an accepted interpretation be superseded by new knowledge? If one would determine that shibolet shual is not oats and that one in fact cannot fulfill their obligation of eating matzah, should we maybe let them eat oat matzah without a blessing in order that they feel part of the mitzvah in some way?
A similar situation arises regarding the use of horseradish to fulfill the mitzvah of eating maror. The preferred maror of the mishnah, ????, was definitely not horseradish and most likely lettuce. So should those Jews who eat horseradish in order to fulfill their obligation of אכילת מרור stop doing so? For an excellent discussion of this question see the article by Arthur Schaffer.
Amar-Zohar Amar, גידולי ארץ ישראל בימי הביניים , Jerusalem 2000
Efrati-in מסורה, אדר תשנ”ג, חוברת יג, עמ’ סו-עא
Felix 1985-הצומח והחי וכלי החקלאות במשנה
Felix 1991-in ספר היובל, מנחה לאי”ש, בעריכת איתמר ורהפטיג, ירושלים, pp. 171-178
Kislev-in ibid., pp. 155-168, 178-185
Low-Die Flora Der Juden
Schaffer-”The History of Horseradish as the Bitter Herb of Passover” in Gesher, vol. 8, pp. 217-237.
Daniel Zohary and Maria Hopf, Domestication of Plants in the Old World, Oxford U Press, 2000.