Schir haSchirim 1:7 Kabbala: Zohar

The moon was not at ease with the sun because she felt embarrassed before it. The moon said to the sun: "Where do you feed your flock? Why do you make your flock to rest at noon?" (Shir Hashirim 1:7). This is as if to say: How can a tiny candle shine in the middle of the day? "Why should I be like one who cloaks himself?" (Ibid.) That is: how can I remain in shame? Then she lowered herself to be head of the lower beings, as it is written: "Go your way forth by the footsteps of the flock" (Ibid. 8). Thus, the Holy One, blessed be He, said to her, 'Go and diminish yourself.'