When Tisha B’Ab falls on Saturday night and Sunday, we do not recite Habdala on Mosa’eh Shabbat as we normally do. Instead, on Mosa’eh Shabbat we recite only the Beracha over the candle ("Boreh Me’oreh Ha’esh"), and on Sunday night, after the fast, we recite Habdala over a cup of wine. The introductory verses of Habdala are omitted in such a case; we recite only "Kos Yeshu’ot Esa" followed by the Beracha over the wine and the Beracha of "Ha’mabdil." The Beracha over the spices ("Besamim") is not recited at all, as it is inappropriate to smell spices on Tisha B’Ab, and once we do not smell the spices on Mosa’eh Shabbat, there is no requirement to smell them on Sunday night.
If a person is ill, Heaven forbid, such that he must eat on Tisha B’Ab (and has consulted with a Rabbi to ensure that he is indeed absolved from fasting), then he must recite Habdala on Mosa’eh Shabbat before eating. Since Halacha forbids eating after Shabbat until one recites Habdala, somebody who must eat on Tisha B’Ab that falls on Mosa’eh Shabbat must recite Habdala before eating.
The question arises as to whether a person may recite Habdala over a cup of wine in such a case. The Talmud speaks in very strong terms about a person who eats meat or drinks wine on Tisha B’Ab, applying to such people the verse, "Their iniquities were upon their bones" (Yehezkel 32:27). This thus gives rise to a dilemma in a case where an ill patient must recite Habdala on Tisha B’Ab in order to be allowed to eat as is medically required. Rabbi Yosef Shalom Elyashiv (Israel, contemporary) ruled that a person in this case should recite Habdala on grape juice, so that he can fulfill the obligation of Habdala without violating the prohibition against drinking wine. Similarly, the Kaf Ha’haim (work by Rabbi Haim Sofer, 1870-1939), in Siman 856 (9), rules that such a person should recite Habdala over beer.
Hacham Ovadia Yosef issues two different rulings on this issue. In his work Yehave Da’at (vol. 3, 40), he writes that a person in this case should recite Habdala over wine and then give the wine to a child to drink, rather than drinking it himself. However, in his more recent work Hazon Ovadia (Laws of Fasts), Hacham Ovadia rules that it is permissible for an ill patient to drink the wine in such a case. He argues that the Talmud’s harsh condemnation of one who drinks wine on Tisha B’Ab refers only to those who do so for pleasure and enjoyment, and with an attitude of indifference toward the observance of Tisha B’Ab. A person who must eat for medical reasons and is therefore required to first recite Habdala most certainly does not belong to this category. Hence, according to Hacham Ovadia, it is in fact permissible to recite Habdala over wine and drink the wine in such a case. This is also the view taken by the Kenesset Ha’gedola (work by Rabbi Haim Banbenishti, Turkey, 1603-1673).
As far as the final conclusion, it would seem that reciting Habdala over grape juice is the most preferable option for such an individual, as it satisfies all opinions.
Summary: When Tisha B’Ab begins on Mosa’eh Shabbat, the Beracha over the candle is recited on Mosa’eh Shabbat, and the rest of Habdala is recited on Sunday night, after Tisha B’Ab, with the exception of the Beracha over spices, which is not recited at all. An ill patient who must eat on Tisha B’Ab is required to recite Habdala before eating. There is a debate among the authorities as to whether one may recite Habdala over wine in such a case, and it is therefore preferable to use grape juice.
