Pesachim, 59a: It implies "Oso", 'me'Erev ad Boker', ve'Ein Davar Acher 'me'Erev ad Boker' - to teach us that this is the only Avodah that lasts from evening until morning - and that consequently, one may not bring any other Korban ¹ after the kindling of the Menorah ² .

Rashi: It implies that the Kohen is obligated to place enough oil each day to burn the entire night. They assessed that half a Log is needed [for each lamp] ¹ for the long nights of Teives, and that is how much they poured in every night, even in summer. ²

Da'as Zekenim, Hadar Zekenim and Rosh (all citing the Riva): They made the wicks thicker or thinner according to the season and the length of the night, ¹ so that the oil always lasted until the end of the night. ²

Ramban: Moshe was to inform the people of the importance of the oil for the Menorah, so that whoever possessed some would donate it. ¹

Moshav Zekenim: [When, in the days of Shimon ha'Tzadik, Yisrael merited] an ongoing daily miracle when the Ner Ma'aravi continued burning throughout the entire day, even though it conained the same amount of oil as the other lamps (which only burned until the morning). This was testimony [that the Shechinah rested in Yisrael].

Oznayim la'Torah: It teaches us that, besides creating light for the Kohanim, the Ner ha'Ma'aravi, which burned permanently, burned in honor of the "Eidus" (the Torah and the Luchos) on the other side of the Paroches.