Why Only Pure Olive Oil Kindles the Menorah Lamps

(Numbers 8:1-2:) "And the LORD spoke to Moses, saying: Speak to Aaron and say to him: When you set up the lamps." Let our master teach us: Is one permitted to kindle with oil of burning on a festival day? Thus our Rabbis taught: One may not kindle with oil of burning on a festival day. [Rabbi Ishmael says: One may not kindle with tar] out of respect for the Sabbath. But the Sages permit all the oils: sesame oil, nut oil, radish oil, [fish oil], gourd oil, tar, and naphtha. Rabbi Tarfon says: One may kindle only with olive oil alone. Rabbi Yochanan ben Nuri stood up on his feet and said: What shall the people of Babylonia do, who have only sesame oil? And what shall the people of Media do, who have only nut oil? [And what shall the people of Alexandria do, who have only radish oil?] And what shall the people of Cappadocia do, who have neither this nor that, but only naphtha? Rabbi Tarfon said to them: Behold, we find that the Holy One, blessed be He, favored olive oil above all the oils for the lamp, and preferred it above all the meal offerings that are brought. Know this: for of all the meal offerings it is said only, "and you shall put oil upon it," but concerning the kindling of the lamp it is written, "pure olive oil." [Therefore Rabbi Tarfon said: One may kindle only with olive oil alone.] And we find that in several places the Holy One, blessed be He, gave instruction concerning the lamps, to kindle with pure olive oil. And thus it says (Exodus 27:20): "that they bring to you pure olive oil." And thus it says: [that they bring to you olive oil, etc.] "upon the pure lampstand he shall arrange the lamps" (Leviticus 24:4). And here too He gives instruction concerning the lamps. From where? From what we read in the matter: "When you set up the lamps," etc.