Bamidbar Rabbah, in section 15, tackles this very question, and the answers are surprisingly profound.

"Toward the front of the candelabrum, the seven lamps shall illuminate," the verse tells us. The Rabbis, however, immediately caution us: don't demean the candelabrum! Don't think it's superfluous. Why? Because God doesn't need our light. As the prophet Zechariah asks in (4:10), "For who scorns the day of small things?" The m’norah and its seven lamps, they correspond to the seven planets that "rove throughout the earth," as Zechariah says. They are so very precious that we mustn't diminish their importance.

The text then points to the design of the windows in the Temple described by Ezekiel (40:16, 25). Notice, it says kehaḥalonot, "like the windows," not kaḥalonot. According to the Rabbis, this subtle difference hints that the windows were designed to be somewhat opaque, kehot, so that the light would emerge outward – a symbol of sharing light with the world.

Rabbi Berekhya HaKohen, speaking in Rabbi's study hall, brings in the concept of primordial fire. Lightning, he says, is a product of supernal fire, illuminating the entire world, just as Ezekiel (1:13) describes the creatures whose "appearance was like fiery coals...and from the fire, lightning would emerge." If that is the source of light, does God truly need our little lamp?

So why did God command us to light the m’norah? The answer is powerful: "It is in order to elevate you."

Rabbi Ḥanina offers another striking analogy: "The eyes that you possess have in them white and black, and you do not see through the white, but rather, through the black. If your eyes, that have in them black and white, you see only through the black, the Holy One blessed be He, who is completely light, does He need your light?"

The text continues: "Flesh and blood kindles from a kindled lamp. Could he, perhaps, kindle from darkness?" The answer, of course, is no. "Darkness upon the face of the deep" (Genesis 1:2). But what happened next? "God said: Let there be light" (Genesis 1:3). God created light from darkness. So, God asks, "From the darkness I produced light, and I need your light? I said it to you only to elevate you: 'to kindle a lamp continually' (Exodus 27:20)."

The m’norah, then, isn't about fulfilling a need of God's. It's about our spiritual elevation. It’s about giving us the opportunity to participate in bringing light into the world, even though the ultimate source of light is beyond our comprehension. It's a humbling and inspiring thought, isn't it? What are the ways we can bring light into the world, not because God needs it, but because we need to give it?