Tomorrow, Friday, will mark the Tenth of Tevet, a public fast day observed throughout the Jewish nation until the arrival of Mashiach which marks the day the king of Babylon besieged Jerusalem with the intent of destroying it. The verse (Yechezkel 24) states: “And the word of Hashem was to me in the ninth year during the tenth month (Tevet) on the tenth day, saying: ‘Son of man! Write for yourself the name of the day, the essence of this very day, for on this very day the king of Babylon laid siege to Jerusalem.’”
The Sages disagree in Masechet Eruvin (40b) what the proper protocol is for when the Tenth of Tevet coincides with Friday, Erev Shabbat. Should the Jewish nation be fasting as we would if the Tenth of Tevet fell out on any other day of the week or perhaps, one should break the fast slightly before the conclusion of Shabbat in honor of Shabbat so as not to enter Shabbat while fasting?
The Gemara (ibid.) quotes a Baraita: “Rabbi Yehuda said: Once, we were sitting before Rabbi Akiva and it was the Ninth of Av which coincided with Erev Shabbat (this cannot happen anymore based on the way our current calendar was set up; however, in the times of Rabbi Akiva, who established the years and months on his own, this was indeed possible). They brought him a slightly cooked egg and he swallowed it without salt. It was not that he desired it; rather, he wished to show the students the Halacha. However, Rabbi Yose said: One must fast and complete the fast.”
This means that Rabbi Akiva broke his fast several minutes before the onset of Shabbat in order to teach the students that one should not enter Shabbat suffering and fasting, for this is considered disrespectful to Shabbat. Nevertheless, Rabbi Yose disagreed with Rabbi Yehuda and ruled that one must complete the fast, as usual.
The Gemara concludes that the Halacha follows the opinion of Rabbi Yose and one must complete the entire fast and eat nothing until Shabbat night Kiddush.
Indeed, the Tosafot quote Rabbeinu Chananel as saying that we have a tradition that Rabbi Akiva was dangerously ill that year and the doctors brought him some food toward the end of the fast. However, Rabbi Yehuda was not aware of this fact and he relied solely on what he saw and he did not know the reason why Rabbi Akiva ate. Thus, even according to Rabbi Akiva, there is no leniency in this regard.
Maran Ha’Shulchan Aruch (Chapter 249) rules that when a fast day coincides with Erev Shabbat, one must complete the entire fast and one may not eat before Shabbat begins.
Thus, Maran Rabbeinu Ovadia Yosef zt”l writes (in his Chazon Ovadia- Arba Ta’aniyot, page 15) that if the congregation prays Mincha and Arvit earlier on Friday afternoon in the synagogue, they may still not make Kiddush until nightfall, which is at approximately fifteen minutes past sunset.
Nevertheless, Hagaon Harav David Yosef Shlit”a writes in his Halacha Berura that according to all opinions, one may not purposely prolong fasting into Shabbat and therefore, Mincha, Kabbalat Shabbat, and Arvit prayers should begin slightly earlier than usual in the synagogue and the Chazzan should move through the prayers quicker than usual so that the congregation can make their way home and recite Kiddush as close to nightfall as possible.