#Plus it's one of the most disorganized Halachic books I've attempted to study

[hyperpotamianarch]

Why is Hannukah eight days if the oil sufficed for one day? Day 5.

Well, today I hit some sort of barrier looking for stuff. Perhaps I should've scoured every commentator on the Shulchan Aruch or the Beit Yosef to find other answers, but I chose to look at a more modern book instead - Aruch HaShulchan. Which, yes, is paraphrasing Shulchan Aruch. Aruch HaShulchan was written by rabbi Yechi'el Michel Epstein about a hundred or less years ago. That proved to... Well, complicate things. You see, Aruch HaShulchan felt somewhat satisfied with Beit Yosef's answers - but only somewhat, because he still felt the need to supply more answers. Being the person I am, though, I wanted to bring you the answers from the earliest origin I can find, and Aruch HaShulchan attributed the answers to someone else: Shiltei HaGiborim on the Mordechai.

I didn't even get to the answer itself, but I feel obligated to note that this is a fascinating route. Shiltei HaGiborim was rabbi Yehoshu'a Bo'az from the Baruch family - don't ask me about the phrasing, please, I'm basing it on his page name in the Hebrew Wikipedia. He was contemporary to the Shulchan Aruch, and rabbi Yosef Karo probably never saw his book. But he also quotes another book that the Beit Yosef did get to see: the Orchot Chaim, by rabbi Aharon HaCohen of Lunel. The latter was a rabbi of the Tosafot era in France, though I think Lunel is in Provence which was an entire thing unto itself at the time. That places us at around the 13th-14th centuries CE, if you were curious.

I could keep the chain of quotes, since the Orchot Chaim also quotes an even older book, but I didn't manage to find this particular point yet in this book, so I'll leave you with what he says: similarly to the answers we had for the previous two days, he has a different topic of celebration for this day. In his case, it's the rededication of the Temple.

That's actually another one that sounds way intuitive. The holiday is called Hannukah, for heaven's sake. In Hebrew, Hannukah means "rededication", or... well, there are a couple of possible translations, it also has to do with education and with initiating use of a house. Re-initiating said use doesn't have a separate word, though. So, yeah. Of course we celebrate the rededication of the Temple, which clearly started at the 25th of Kislev.

This answer is not without problems, but neither are the two of yesterday and the day before. By suggesting a different cause to celebrate on the first day from the other days you create a conundrum of why, then, are they all celebrated the same? With the answer from Shabbat, on the victory in the war, there's a rebuttal from the Turei Zahav saying that a victory in the war requires days of feasting and joy, like Purim. Since this wasn't the prominent component of the miracle, though, the days of Hannukah are days of Praise and Thanks, which is why the Hallel is a central commandment of the holiday but feasting is not - unless it contains praise to Hashem on the miracle. This actually has Halachic ramifications.

Tomorrow, if I'll manage to find the source, we'll talk about the other answer suggested in the Orchot Chaim, which is widely different from all the answers we've seen yet.