The Sages taught in a baraita: The basic mitzva of Hanukkah is each day to have a light kindled by a person, the head of the household, for himself and his household. And the mehadrin, i.e., those who are meticulous in the performance of mitzvot, kindle a light for each and every one in the household. And the mehadrin min hamehadrin, who are even more meticulous, adjust the number of lights daily.

Beit Shammai and Beit Hillel disagree as to the nature of that adjustment. Beit Shammai say: On the first day one kindles eight lights and, from there on, gradually decreases the number of lights until, on the last day of Hanukkah, he kindles one light.

And Beit Hillel say: On the first day one kindles one light, and from there on, gradually increases the number of lights until, on the last day, he kindles eight lights.

Ulla said: There were two rabbis in the West who disagreed about the reason for Hillel and Shammai's opinions, Rabbi Yosei bar Avin and Rabbi Yosei bar Zevida. One said that the reason for Beit Shammai’s opinion is that the number of lights corresponds to the incoming days, i.e., the future. The reason for Beit Hillel’s opinion is that the number of lights corresponds to the outgoing days.

And one said that the reason for Beit Shammai’s opinion is that the number of lights corresponds to the bulls sacrifced (which decreased over time) and the reason for Beit Hillel’s opinion is that the number of lights is based on the principle: One increases the holy, one does not decrease it.