The Spirit of all Flesh

(20) and ה׳ spoke to Moses and Aaron, saying, (21) “Stand back from this community that I may annihilate them in an instant!” (22) But they fell on their faces and said, “O God, Source*Source Lit. “God.” of the breath of all flesh! When one member*member sins, will You be wrathful with the whole community?”

Koren: And they fell upon their faces, and said, O God, the God of the spirits of all flesh, shall one man sin, and wilt thou be angry with all the congregation?

Everett Fox:

They flung themselves on their faces and said:
O God, God of the spirits of all flesh,
when one man sins,
at the entire community will you be furious?

(15) Moses spoke to ה׳, saying, (16) “Let ה׳, Source of the breath of all flesh, appoint someone over the community (17) who shall go out before them and come in before them, and who shall take them out and bring them in,*who shall go out … and bring them in I.e., who shall lead them in all matters and whom they shall follow in all matters. so that יהוה’s community may not be like sheep that have no shepherd.” (18) And ה׳ answered Moses, “Single out Joshua son of Nun, an inspired man, and lay your hand upon him.

(1) After that,
I will pour out My spirit on all flesh;
Your sons and daughters shall prophesy;
Your elders shall dream dreams,
And your youths shall see visions.

I will pour out my spirit upon all flesh - meaning on Israel similar to what it says in a different place "all flesh" and it doesn't mean to any living thing, but only to humans, and it says to bless call flesh, here also it comes to limit, so here too, "all flesh" refers to Israel who are fitting to have the holy spirit on them.

On the expression: "God of the spirit of all flesh"

Moses our Teacher use here a very strange title which is also singular in all of scripture.

Considering that we go back and read here what appears to be the reasoning for the decree passed on him (Korach) - "When you lifted up your mouth in the Wilderness of Tsen in the strife of the congregation to consecrate me with water before their eyes" (Bamidbar 27:18), the phrase "the God of the spirits to all flesh" evokes in us the impression, as if Moses Alludes to her - 'You who know hidden things and know the spirit of all flesh, visible and known before you from my conscience - that I have not sinned'.

“A man in whom there is spirit” – because he had said: “God of the spirits” (Numbers 27:16); as You know the spirit of each and every one of Your creations, and You should appoint a person who knows how to conduct himself with each and every one of them in accordance with his own disposition.
“And lay your hand upon him” – like one kindling from lamp to lamp. “You shall confer from your grandeur [upon him]” (Numbers 27:20) – like one pouring from vessel to vessel.
What you said: “An inheritance shall not pass from one tribe to another tribe” (Numbers 36:9) – this honor will not move from your patrilineal house, as, even Joshua who is standing in your stead, “before Elazar the priest he shall stand” (Numbers 27:21).

Since he went with the strict according to their opinion and with the moderate according to their opinion

A God who knows the thoughts and spirit of each individual who is proud and who is humble, who is easy going (with his fellow) and who is demanding [and also he said who "he who fashions their hearts alike; who considers all their deeds Psalms 33: 15 and says: "Every way of a man is right in his own eyes: but the Lord weighs the heart." Provers 21: 2

SEPARATE YOURSELVES FROM AMONG THIS CONGREGATION, THAT I MAY CONSUME THEM IN A MOMENT. ... At first the heart of the people was on the side of Moses and Aaron, but when Korach and his company took every man his censer and laid incense thereon and stood at the door of the Tent of Meeting with Moses and Aaron, Korach called together all the congregation and told them that he was concerned about the honor of all of them. This was pleasing to them, so they all assembled to see peradventure it will be right in the eyes of G-d, and the service [of the offerings] will return to their firstborn, this being the meaning of the verse, And Korach assembled all the congregation against them. Thus they [all] became liable to destruction because they cast aspersions on their teacher, which is like casting aspersions on the Divine Presence, and they [likewise] rejected in their hearts the prophecy of a prophet, for which they were liable to death by the hand of Heaven. But Moses and Aaron spoke up in their defense, saying that it was only Korach who sinned in this matter, for he was the cause of it all and it was he who incited them, therefore it was right that he alone should die, in order to publicize and make known his punishment to the [whole] community.
This is indeed the way of those who plead for mercy, for they mitigate the [severity of the] people’s sin, and put [the blame for] it upon the individual who caused it, because he at any rate is [certainly] guilty. And so did David say, Lo, I have sinned, and I have done iniquitously; but these sheep, what have they done? Let Thy hand, I pray thee, be against me, and against my father’s house.

Whoever commits this sin is an utterly wicked person. All the mitzvot that he performs throughout his lifetime cannot outweigh this sin and save him from judgment. Thus, Proverbs 28:17 states: "A man weighed down with life's blood will flee to the pit."
Come and learn from the example of Ach'av King of Israel. He was an idolater so debased in his paganism that I Kings 21:25 says: "There was none like Ach'av who gave himself over to the performance of wickedness in the eyes of God." And yet when his merits and sins were weighed in the presence of the Lord of spirits, there was no sin that warranted his destruction and was not counterbalanced by a positive quality, except the blood of Navot.

(42) Since it is impossible to form a representation of Him with the intellect or picture Him with the imagination, we find that Scripture ascribes most of its praises to the "Name" of G-d, as written: "And they shall bless Your glorious Name" (Nehemiah 9:5), and "that you may fear this glorious and revered Name" (Deut. 28:58), and "Let them praise Your Name, great and revered" (Ps. 99:3), and "of My Name he was afraid" (Malachi 2:5), and "But unto you that fear My Name shall the sun of righteousness arise with healing in its wings" (Malachi 3:20), and "Sing unto G-d, sing praises to His Name, extol Him that rides upon the skies, whose Name is the L-ord" (Ps. 68:5).

(43) All this is in order to honor and exalt His glorious essence because, besides clarifying that He exists, it is impossible for us to clarify in our minds anything about His Being except for His great Name.

(44) But as for His glorious essence and His true nature - there is no picture or likeness that we can grasp in our minds. Therefore, His Name is frequently changed in the Torah and likewise in the books of the prophets.

(45) Because we cannot understand anything about Him except for His Name and that He exists. His glorious Name is also associated with heaven and earth and the Spirits, as Abraham said: "And I will make you swear by the L-ord, the G-d of heaven and the G-d of the earth" (Gen. 24:3), and Yonah said: "I fear the L-ord, the G-d of heaven" (1:9), and Moshe said: "the G-d of the spirit of all flesh" (Numbers 27:16). And the verse proclaims: "Behold, I am the L-ord, the G-d of all flesh" (Yirmiya 32:27).

(46) The reason for this is that He is known to us in the way possible through the traditions of our forefathers from whom we have inherited the knowledge of His ways, as written "For I have known him (Abraham), to the end that he may command his children and his household after him, that they may keep the way of the L-ord, to do righteousness and justice" (Gen. 18:19).

(47) Perhaps, G-d revealed Himself to them because they were the only ones in their generation who took on to serve Him since the people of their generation worshipped other "gods" (idols, sun, moon, money, etc.)

(48) Similarly we will explain for His being called (in scripture) "the G-d of the Hebrews" (Ex. 3:18), "the G-d of Yisrael" (Gen. 33:20), as the verse says "not like these is the portion of Yaakov for He is the Creator of all" (Yirmiya 10:16).