Musar zu Bamidbar 29:12

The Talmud Shabbat 21b quotes a Baraitha according to which it is obligatory to kindle one Chanukah light per household, whereas if one wishes to perform the מצוה in the best possible way every member of the household kindles a light in commemoration of the great miracle that occurred at the time. Those who wish to excel still further in their מצוה performance light an additional light every evening of the eight evenings in question according to the school of Hillel, or, according to the school of Shammai, they light eight lights the first evening and one light less every subsequent evening. Ullah says that two scholars (Rabbi Yossi bar Avin and Rabbi Yossi bar Zevida) disagreed as to why the school of Hillel and the school of Shammai in turn disagreed on the proper course to follow. One Rabbi said that the reason that the school of Shammai holds that one kindles one light less each evening is that the number of lights indicates how many days of the holiday are still to come, (the literal quote is ימים הנכנסים, we adopt Rashi's translation of this, however), whereas the school of Hillel is concerned with the number of days of the holiday that have already passed. The other Rabbi holds that the difference between the two schools of thought is due to the school of Hillel holding that in matters of sanctity one progresses "upwards," i.e. מעלין בקודש ואין מורידין. The reason that the school of Shammai holds that one kindles one less light each night, however, is that we follow the pattern established by the Torah on Sukkot, when successively fewer bulls were offered on each of the seven days of the holiday (Numbers 29,12-34). Rabbi Bar Chanah reported in the name of Rabbi Yochanan that the two Rabbis Yossi quoted were flanked by two elders, one of whom followed the directive of the school of Shammai, whereas the other followed the directive of the school of Hillel. Each of those two elders justified his practice by citing the last two reasons mentioned. Thus far the Talmud on the subject.