By: Meoros HaDaf HaYomi
Cooking is a labor (melachah) forbidden on Shabbos, occurring when liquid or solid foods or other substances improved by heating, like pigments, are even parboiled. Utensils containing hot liquids are defined in three categories: A primary utensil (keli rishon) holds a boiling liquid and continues to be primary even off the fire or electric plate as long as an average adult’s hand recoils from its contents. Liquid poured directly from there cooks the external layer of any solid, uncooked food and a small amount of any cold liquid, even water (Shulchan ‘Aruch, O.C. 318:10; see Mishnah Berurah, ibid, S.K. 82). A container having received liquid from a keli rishon is called a second utensil (keli sheni) and likewise cooks in many circumstances as long as one’s hand recoils from its contents. A container receiving liquid from a keli sheni is a third utensil (keli shelishi) and virtually never cooks.
Making a glass of tea on Shabbos: A person wanting to make a hot drink on Shabbos might rinse a cup, inadvertently neglect to dry it or shake it out thoroughly and pour boiling water into it from a keli rishon. Most halachic authorities forbid this as the boiling water cooks the small amount of cold water in the cup (see Responsa Igros Moshe, O.C., I, 93; Responsa Minchas Yitzchak, IX, 30). They raise the question as to whether cooking a few drops of water is actually prohibited by the Torah – d’oraisa – or by rabbinical decree (derabanan). As we shall see, the topic is linked to Rashbam’s interpretation of a certain example cited in our sugya.
Rabbi Yochanan holds that “half a prohibited quantity is forbidden by the Torah” (Yoma 74a). Forbidden substances or acts are quantified according to measures received by Moshe Rabbeinu at Sinai. The minimal amount of food prohibited on Yom Kippur, for example, is equivalent to the volume of a large date. A person eating less is not punishable but, according to Rabbi Yochanan, is still forbidden to do so by the Torah. [“Half a quantity” does not mean only a half but rather, less than the halachically prohibited amount; we shall therefore hereon use the term “subquantity.”] Many Rishonim maintain that this rule also applies to Shabbos (Rashi, Shabbos 74a, s.v. Vechi mutar; Ritva and Hagahos Ashri, ibid; see Mishneh LeMelech, Hilchos Shabbos, 18:1). For instance, according to Rambam, the quantity of water forbidden to heat on Shabbos is enough to wash a baby’s pinky (Hilchos Shabbos, 9:1). Following the above opinion, someone boiling less is not punishable in any earthly beis din, but is still prohibited from doing so by the Torah. Some halachic authorities, though, cite Rashbam’s reasoning that this principle does not pertain to Shabbos.
The amount of food forbidden to carry on Shabbos from a reshus hayachid (literally, a “private domain” but actually any area, even ownerless, bound by certain enclosures) to a reshus harabim (a public domain having a certain breadth and other conditions) is equivalent to the volume of a dried fig. Our sugya mentions a person who carries out a subquantity of food and, according to Rashbam (s.v. Bemaseches Shabbos), he is innocent of any transgression as the Torah calls Shabbos labor meleches machsheves: “skilled” or “important” work. Shabbos labor is quantified by its importance, a condition that defines melachah, and a subquantity is therefore not melachah at all. By comparison, eating a subquantity on Yom Kippur is still eating and a partial transgression of the “affliction” demanded by the Torah (Vayikra 17:29). [This meaning is just one definition of meleches machashaves; see also Rashi in Chagigah 10b.] A subquantity of any prohibition, though, is outlawed at least derabanan (see Shabbos, ibid) and we must therefore assume that Rashbam would rabbinically forbid pouring from a keli rishon on a subquantity of cold water, such as in our example (see Responsa Divrei Yatziv, O.C. 156; Responsa Shevet HaLevi, VII, 136).