This is another reason why he is called Elijah and not Pinchas. Through this act he merited a name change, as we will explain later regarding the matter of Elisha the prophet. Once they were rectified they did not need to remain there, and Nadab and Abihu were withdrawn.

Now Jezebel the wife of Ahab was a great sorceress - it says that she caused Israel to go astray [to idolatry] through her magic. Through her magic she knew that Nadab and Abihu, of whom it was declared, "Behold, I give to him my covenant of Shalom," (Num. 25:12) which means eternal life, had been withdrawn from Elijah.

...the decree of life and peace was removed from him.

Thus she told him, "At this time tomorrow, I will make your nefesh [life] like the life of one of them [who were killed]" (Kings I 19:2) - since the decree of life and peace was removed from him. There is also a connection to Nadab and Abihu who were burned by the fire of the incense. This is the secret of, "like the nefesh [life] of one of them [Nadab and Abihu1]." Since Elijah felt that this gift was taken from him he became afraid and fled to Mt. Horeb. This is what is written, "And he saw, and he arose and went for his nefesh [life]." (Ibid. 3) That is, he saw that he had only one nefesh [soul], and so feared Jezebel.

He found respite in the cave at Mt. Horeb [Sinai2], until he went up in a storm wind to Heaven. It was Elijah the Tishbite from the tribe of Gad who ascended to Heaven and he did not descend again. However, Elijah from the tribe of Benjamin reincarnated into the one mentioned in the verse, "And Jaareshiah, and Elijah, and Zichri were the sons of Jeroham." (Chron. I 8:27) Later when he died, he ascended to join Elijah who had ascended.

It is Elijah from the tribe of Benjamin who ascends and descends constantly to perform miracles for the righteous and to speak with them. (Shaar Ruach HaKodesh)

At first, the sages only knew that Elijah was comprised of four levels, but they did not know which level descended and ascended and spoke with them. They differed in opinion, until he told them, "My Rabbis ... why are you disagreeing over me? I come from the children of Rachel, as it says, ‘And Jaareshiah…Elijah’". Thus, he revealed to them which level it was that spoke to them, the level of Elijah of Benjamin, which is joined together with the drop from Jethro that was given to Hiel Bait Ha’eli. After he had died, Elijah took it with him.

It seems to me the author that the two of them reincarnated into Elijah of Benjamin. Elijah gave the level called the drop of Joseph to [the prophet] Jonah, son of Amitai the Tsarafite when he revived him. (Kings I 17:17-23) This is the secret of what is written in the Zohar, "It was taught: Jonah came from the legion of Elijah, which is why he is called, "son of Amitai [son of Truth]," As it says, "and that the word of G‑d in your mouth is truth!" (Kings I 17:24, Zohar II Vayakhel 197a)

This is the secret of why Jonah is also a great man of truth and he underwent and survived miniature state of death when he was swallowed by the whale. (Jonah, Zohar Yonah)

"The lad that I revived was Mashiach son of Joseph."

This is also the secret of what the Sages write, "It was taught in the school of Elijah, "The lad that I revived was Mashiach son of Joseph." Since he came from a drop of Joseph he will therefore be Mashiach ben Joseph - may it happen speedily in our time!

The part that remained for Elijah in the future was that of the tribe of Benjamin. The ibur of Nadab and Abihu was given to Elisha [his disciple] in the secret of ibur, when he ascended to Heaven. This is the secret of what Elisha requested, "Na [please], may twice as much of your spirit be mine." (Kings I 2:9) In Sefer Hakanah it says, "twice as much" - that is Nadab and Abihu.

That is the NA/na [please] that he added, which is made up of the first letters of Nadab and Abihu - they are the double portion that was added to the ruach of Elijah. Also, the first letters of "Na pi shnayim biruchacha alai [Please, may twice as much as your spirit be mine]" spell nefesh bah [the soul comes], that is, Nadab and Abihu who were the level of the nefesh of Atzilut of Adam, which had come to him when he had killed Zimri. [Elisha requested,] "Give them to me."

The extra souls are hinted to in NA/please - asking permission before taking. For they come to fix the defect of Nadab and Abihu, which involved entering the holy of holies and offering incense "that they were not commanded" - a drawing/taking of light without permission. Elijah/52 equals3 NA-51, showing that this is part of his intrinsic tikun.

This fixed the very foundations of the tikun that was then happening. For we know that the Cain root comes from the world of Tohu. There, too much light was forcibly poured into the vessels. Simply saying ‘please’ is a great reparation of this root. For the elite who are possessed by yearning for light, this can at times actually be a test.

What comes out is that Elisha asked for the double portion of spirit that Elijah had - Nadab and Abihu. The Talmud interprets this to mean that Elijah revived one person from the dead, Elisha two.4 Rabbi Nachman explains that a disciple can receive double his teacher’s spirit - specifically at the time of the mentor’s departure. For then the upper aspect of his soul comes down to take away the lower aspect. The teacher, whose time it is to go, leaves, whereas the student receives an infusion from the upper soul that leaves him with a double helping. This is the secret of Elisha asking for it, and Elijah telling him that if he is present when he departs from the world the request would be fulfilled.5

[Translation and commentary by Perets Auerbach.]