The Prohibition of Turning on an Incandescent Bulb on Shabbat by Rabbi Chaim Jachter



            We have often taken for granted in numerous past essays that turning on an electric appliance in which a filament is heated until it glows constitutes a violation of Torah law.  Although there is great debate whether completing a circuit in an appliance in which a filament is not heated until it glows  is a Biblical or Rabbinic level prohibition,  a clear consensus has emerged concluding that turning on an appliance with a glowing filament violates a Torah prohibition.  In this essay we will explore the basis and development of this consensus view.


Four Talmudic Passages

            There are four passages in the Talmud which discuss heating metal on Shabbat.  In Yevamot 6b, the Gemara states that melting metal on Shabbat in preparation for use in administering the form of capital punishment known as "S`refa" (burning) involves two violations of the laws of Shabbat.  The two violations are cooking (Mevashel) and burning (Mavir).  The Avnei Neizer (Orach Chaim 229) asserts that this Talmudic passage is the prime source which indicates that one who heats a metal violates a Torah level prohibition.  The second source is the Gemara on Pesachim 75a which records a dispute between Rav Chisda and Ravina whether a Gachelet Shel Matechet is defined by the halacha as fire.

            The Gemara in Yoma 34b relates that if the Kohein Gadol found it difficult to immerse in a cold Mikvah, iron bars were heated prior to Yom Kippur and placed into the Mikva used by the Kohein Gadol.  This is speaking of a Kohen Gadol who found it difficult to immerse in a cold Mikvah.  The Maggid Mishnah (commenting on Rambam Hilchot Shabbat 12:1) points out that we see from this Gemara that heating a metal involves violating a Biblical level prohibition.  Had the Gemara regarded heating a metal as only a Rabbinic level prohibition, it would have permitted heating the metal rods on Yom Kippur.  This is because of the celebrated rule "Ein Shvut Ba-Mikdash," Rabbinic prohibitions do not apply in the Beit Hamikdash.

            Nonetheless, the Maggid Mishnah's proof is not beyond dispute.  The counter argument is that indeed heating metals is merely a Rabbinic level prohibition, but nevertheless we do whatever is necessary to minimize violating rabbinic prohibitions even in the Beit Hamikdash. The following sources support this contention: Eruvin 103a, Rambam Hilchot Korban Pesach 1:18, and the commentary ad. loc. of the Lechem Mishna.

            The fourth passage is Shabbat 74b which defines heating a metal to soften it as an act of Bishul.

            The Rambam (Hilchot Shabbat 9:6) rules that heating a metal constitutes a Tolada (subcategory) of the Melacha of cooking.  In Hilchot Shabbat 12:1 the Rambam rules that heating a metal is a Tolada of the Melacha of Mavir (burning).  The Raavad (commenting on the Rambam Hilchot Shabbat 12:1) asserts that the act of heating a metal is only considered Bishul.

            The Avnei Neizer (O.C. 229) explains that the Rambam and Raavad disagree as to whether the Halacha follows Rav Chisda or Ravina in their debate on Pesachim 75a as to whether a Gachelet Shel Matechet constitutes a fire. The Raavad rules that a heated metal is not considered to be fire. Rav Shlomo Zalman Auerbach (Teshuvot Minchat Shlomo pp.105-107) disputes this interpretation and offers an alternative interpretation. Normative Halacha accepts the opinion of the Rambam (see Shaar Hatzion 318:1; Chayei Adam 45:2; and Chashmal Le-or Ha-halacha p.41 and p.48).  The Chazon Ish (Orach Chaim 50:9) and Rav Shlomo Zalman Auerbach (Minchat Shlomo p. 107) disagree about the temperature at which one violates the prohibition of heating a metal.  The Chazon Ish rules that the violation occurs at the point that the metal becomes Yad Soledet Bo (hot to the touch).  Rav Shlomo Zalman argues that the heating of metal is Halachically  insignificant until the metal heated to the point that it appears as a glowing coal.  Rav Moshe Feinstein concurs with Rav Shlomo Zalman's conclusion disputing the Chazon Ish.  The Rambam appears to contradict himself as to whether heating a metal constitutes Bishul or Havarah. In Hilchot Shabbat 12:1 the Rambam writes that it is Havarah and in Hilchot Shabbat 9:6 he writes that it is Bishul.  Lechem Mishna (commenting on Hilchot Shabbat 12:1) explains that one violates different prohibitions depending on the stage of the process of heating metal which has been reached.  Bishul is violated at the temperature at which the metal can be softened.  At the point that the metal can be tempered, Havarah is violated.  The Lechem Mishna's approach to this problem is widely accepted (see Shaar Hatzion 318:1 and Teshuvot Tzitz Eliezer 3:17) though the Chazon Ish (O.C. 50:9) presents a very different way to resolve this apparent contradiction in the Rambam. 


Incandescent Lamps

            When the incandescent bulb (which is essentially a glowing metal caused by the resistance in the wire to the electric current flowing through it) was introduced during the latter part of the nineteenth century, poskim argued whether lighting such bulbs constitutes an act of Bishul or Havarah.  The Maharsham (2:246) suggested that lighting an incandescent bulb was only a rabbinic prohibition, due to the dissimilarity between an incandescent bulb and the fire created in the Mishkan.  He noted that the incandescent bulb more resembled the Biblical burning bush (fire that does not consume) than the fire in the Mishkan.  Rav Eliezer Waldenberg (Tzitz Eliezer 1:20:6) vigorously refutes the Maharsham's suggestion.  The fact that the Rambam's opinion that heating a metal until it glows violates Havara clearly indicates that a glowing metal constitutes a fire.  The Halacha rejects the suggestion of the Maharsham.  Both the Tchebiner Rav (Teshuvot Doveiv Meisharim 1:87) and Rav Ovadya Yosef (Teshuvot Yabia Omer I:19) assert that the Maharsham's suggeston cannot be utilized even as a Sniff Lehakel, a component in the lenient ruling.  The Chazon Ish (O.C. 50:9) writes that since the wires in an incandescent bulb are heated, turning on an incandescent bulb constitutes an action of Bishul.  Rav Shlomo Zalman Auerbach, however, notes that since one does not care that the metal within the bulb is softened, one doesn't perceive the softening of the metal within the lamp.  Moreover, the metal returns to its original state immediately when the light is extinguished. Thus, argues Rav Shlomo Zalman, the halacha attaches no significance to the fact that the metal is softened.  Thus, lighting an incandescent bulb is not considered to be an act of "bishul."  Rav Moshe Feinstein presents a similar argument to that of Rav Shlomo Zalman Auerbach (see Igrot Moshe O.C. III:50).

            Most authorities agree with Rav Shlomo Zalman (Minchat Shlomo no. 12) that turning on an incandescent bulb is considered to be an act of Havara.  Rav David Tzvi Hoffman (Teshuvot Melamed Lehoil I:49) states what has emerged as the consensus opinion.  "Havara" refers to the creation of light and not the burning of fuel.  Almost all authorities find the analogy between an incandescent bulb and the Rambam's heated metal to be compelling.  Achiezer (3:60), Minchat Shlomo (no. 12), Tzitz Eliezer (3:1), Mishpetei Uzziel (II O.C. 36), and Beit Yitzchak (Y.D. 1:120) are some of the major authorities who rule that causing a filament to glow constitutes an act of Havara.

            It is related by many (including Rav Yosef Dov Soloveitchik) that Rav Chaim Ozer Grodzinski (the preeminent halachic authority of pre- World War II European Jewry) used to routinely use an incandescent bulb for the fire of Havdalah.  He did so in order to emphasize to all that an incandescent light constitutes a fire.  On the other hand, there is great debate as to whether a Biblical or Rabbinical prohibition is violated if one turns on an appliance in which a glowing filament is not present (see Chazon Ish O.C. 50:9  and Teshuvot Minchat Shlomo no. 11).

            Next time we will discuss the permissibility of opening refrigerators on Shabbat.

Opening Refrigerators on Shabbat by Rabbi Chaim Jachter

When to Make the Bracha on the Arba Minim by Rabbi Chaim Jachter