There is a Misva to recite on Mosa’eh Shabbat the Beracha of "Boreh Me’oreh Ha’esh" over a flame. Adam Ha’rishon produced the world’s first flame on Mosa’eh Shabbat, and we therefore commemorate and give thanks for the creation of fire on Mosa’eh Shabbat by reciting this Beracha. The Beracha is formulated in the plural form – "Me’oreh Ha’esh" – because fire consists of several different colors.
The Shulhan Aruch (Orah Haim, end of 298) rules that one may not use for this purpose a lantern, that is, a flame contained within a glass casing. Even if the glass is transparent and the flame is thus clearly visible, nevertheless, one may not recite the Beracha of "Boreh Me’oreh Ha’esh" over a covered flame. Although the Rashba (Rav Shlomo Ben Aderet of Barcelona, Spain, 1235-1310) maintains that the Beracha may be recited over a covered flame, as long as the glass is transparent, and several Halachic authorities (Magen Abraham, Aruch Ha’shulhan) adopted his position, this was not Maran’s opinion. Therefore, one must use an exposed flame for the Beracha of "Boreh Me’oreh Ha’esh" on Mosa’eh Shabbat.
On the basis of this Halacha, Hacham Bension Abba Shaul (Israel, 1923-1998) ruled that one may not recite the Beracha over the light of a bulb. Even though the light is produced by a fire, the Beracha may not be recited over this light because the kindled filament is contained within a glass case. This is also the view of Hacham Ovadia Yosef, in his Yabia Omer (vol. 1), who adds that since the Beracha commemorates the flame produced by Adam Ha’rishon, it must be recited over a flame that resembles that flame, which was exposed and not covered.
The Beracha of "Boreh Me’oreh Ha’esh" is also recited on Mosa’eh Yom Kippur. The reason for reciting the Beracha on Mosa’eh Yom Kippur is to demonstrate that use of fire had been forbidden throughout Yom Kippur – as opposed to other festivals, when fire may be kindled from an existing flame – and is now permissible. Accordingly, the Shulhan Aruch (624) rules that the Beracha may be recited on Mosa’eh Yom Kippur only over a flame that had been lit before Yom Kippur. Since the purpose of the Beracha is to demonstrate the permissibility of using fire, it requires a flame that had been lit during Yom Kippur and was forbidden. This is in contrast to Mosa’eh Shabbat, when the purpose of the Beracha is to commemorate the original creation of fire, and thus it is recited over a new flame.
The Shulhan Aruch rules that if one does not have on Mosa’eh Yom Kippur a candle that had been lit before Yom Kippur, then he does not recite the Beracha. This is the position accepted by Hacham Ovadia Yosef. It should be noted, however, that the Beracha may be recited over a candle that was lit on Mosa’eh Shabbat from a candle that had been lit before Yom Kippur. As long the flame originated from a flame kindled before Yom Kippur, it is suitable for the Beracha.
Summary: The Beracha of "Boreh Me’oreh Ha’esh" is recited on Mosa’eh Shabbat over an exposed flame; it may not be recited over a flame covered by glass, such as a lantern or lightbulb. The Beracha is recited on Mosa’eh Yom Kippur, as well, but only over a candle that had been burning since before Yom Kippur, or a candle that was lit from a candle that had been burning since before Yom Kippur.
