Daf Yomi - Taanis 25 - Vinegar Can Burn

The Gemora records an incident with Rabbi Chanina ben Dosa. One Friday night, Rabbi Chanina noticed his daughter in a despondent mood. Upon asking her what the trouble was, she replied: "I got the two vessels containing oil and vinegar mixed, and poured the latter into the Shabbos lamp and lit it." He said: "My daughter! Why should that trouble you? He who has ordained that oil should burn can also ordain that vinegar should burn." We have learned in a braisa that the vinegar in that lamp burned all night and all day, until some of it was used for the Havdalah prayer.

With this Gemora, Reb Dovid Feinstein answers the famous question of the Beis Yosef on Chanukah. Why do we celebrate Chanukah for eight days when the miracle was only for seven?

The Sages chose Chanukah, a festival that revolves around oil's ability to burn, as the time to teach the fundamental truth that even so-called "natural" events take place only because God wants them to. When seen in the perspective of God's will, the burning of oil is no less miraculous than would be the burning of water. The Talmudic Sage Rabbi Chanina Ben Dosa pithily expressed this truth in explaining a miracle that occurred in his own home. Once, his daughter realized that she had poured vinegar instead of oil into the Sabbath menorah. Rabbi Chanina calmed her, saying, "Why are you concerned! The One Who commanded oil to burn, can also command vinegar - and it will burn!" The Talmud goes on to relate that those Sabbath lights remained aflame until after the Sabbath ended (Taanis 25a). To hammer home this truth, the Sages decreed that Chanukah be observed for eight days: The last seven to commemorate the miracle of the Menorah, and the first to remind us that even the 'normal' burning of oil is only in obedience to God's wish. (Rabbi David Feinstein)