When Purim falls on Mosa’eh Shabbat (as it does this year, 5771), we recite Arbit at the end of Shabbat as usual, with "Shuba," "Viyhi Noam" and "Yosheb Be’seter Elyon." After "Yosheb Be’seter," however, rather than proceeding with "Ve’Ata Kadosh," we recite the Beracha of "Boreh Me’oreh Ha’esh" over a flame. We may not derive benefit from light on Mosa’eh Shabbat until we recite the Beracha over a flame, and we must therefore recite this Beracha before reading the Megila.
After reciting the Beracha over the flame, we read the Megila and complete the Tefila, and then recite the rest of Habdala. Of course, the Beracha over the flame is omitted, since it had already been recited before the Megila reading.
If a woman was not present in the synagogue for Habdala, and her husband – who had heard Habdala in the synagogue – thus recites Habdala for her at home, she should preferably recite the Beracha over the flame herself, rather than have her husband recite the Beracha for her. This is the ruling of Hacham Ovadia Yosef. However, if she is unable to recite the Beracha herself, then the husband may recite the Beracha for her.
If a congregation forgot to recite the Beracha over a flame before the Megila reading, and they realized their mistake during the reading, they should interrupt the reading in between two paragraphs of the Megila to light a candle, and the Hazan then recites the Beracha. Of course, if they realized their mistake only after the completion of the reading, then they simply include "Boreh Me’oreh Ha’esh" in the recitation of Habdala after the reading.
Summary: When Purim falls on Mosa’eh Shabbat, the Hazan in the synagogue recites the Beracha over a flame before "Ve’Ata Kadosh," and then the Megila is read. After the Megila reading, the Arbit service is completed and then the rest of Habdala is recited. If a husband heard Habdala but then recites Habdala for his wife at home, it is preferable for her to recite the Beracha over the flame herself. If the congregation forgot to recite the Beracha over the flame before the Megila reading, and they remembered during the reading, they should interrupt the reading to light a candle and recite the Beracha.
