Kabbalah su Isaia 51:6

Why did the Holy One, blessed be He, create the worlds if he intended to destroy them? It would have been better had he not created them at all. But there certainly must be a secret here. What is the meaning of, 'He destroyed them'? It cannot be that the Holy One, blessed be He, destroyed the makings of His own hands. Furthermore, these are the heavens about which it is said, "For the heavens shall vanish away like smoke..." (Isaiah 51:6). If it is so, then the Holy One, blessed be He, first created and then destroyed (what He created).

So the letter Vav came down together with (Moshe to) guard him, so he does not perish among them, because according to the secret of reincarnation, he was destined to mingle among the mixed multitude in exile, whose souls originated from the aspect of those of whom it is written: "For the heavens shall vanish away like smoke" (Isaiah 51:6). These are the ones for whom Noah did not plea for mercy. About them, it is written: "They were destroyed from the earth" (Beresheet 7:23), because they came from those of whom it is said, "You shall blot out the remembrance of Amalek" (Devarim 25:19). Moses did not protect himself from them and dropped the (small) Hei among them. For this reason, he shall not enter the land of Yisrael until he brings the Hei back to its place. This is also why he fell from his grade, and the letter Vav descended with him. Because of this, the letter Hei fell down and the letter Vav of Moses shall raise it up.