The place to start our understanding of the 'heavenly man' concept is to go to the so-called Wisdom of Solomon 18:15 - 17 where Marcion's 'man of war' (= πολεμιστὴς) who resides in heaven is clearly portrayed:
Thine Almighty λόγος leaped down from heaven out of thy royal throne, as a fierce man of war into the midst of a land of destruction, And brought thine unfeigned commandment as a sharp sword, and standing up filled all things with death; and it touched the heaven, but it stood upon the earth.
ὁ παντοδύναμός σου λόγος ἀπ᾿ οὐρανῶν ἐκ θρόνων βασιλειῶν ἀπότομος πολεμιστὴς εἰς μέσον τῆς ὀλεθρίας ἥλατο γῆς, 16 ξίφος ὀξὺ τὴν ἀνυπόκριτον ἐπιταγήν σου φέρων, καὶ στὰς ἐπλήρωσε τὰ πάντα θανάτου· καὶ οὐρανοῦ μὲν ἥπτετο, βεβήκει δ᾿ ἐπὶ γῆς
It has been argued - convincingly I think - that Wisdom 18:15 is behind Hebrews 4:12's reference to God's word being likened to a sword (and possibly Matt 10:34).
Once we move beyond the idea that Jesus is the 'man of war' here it is possible to see that groups at the turn of the Common Era imagined that the 'heavenly man' was איש. Of course it must be said that the 'Adam' in the first chapter of Genesis cannot be the איש. First of all, he was created 'male and female' and the Marcionite איש was clearly undivided. Philo, I think, supports this notion when he speaks of a God in whom this 'heavenly Adam' was modeled after. This heavenly man was after all 'the world,' which might help explain Paul's statement - δι’ οὗ ἐμοὶ κόσμος ἐσταύρωται κἀγὼ κόσμῳ (Gal 6:14)
The image of this heavenly man in a chi shaped cross is enough to make Justin connect the image with Plato's World Soul. Clearly something like this is being hinted at in the symbolism. The Christians must have drawn from this idea of a 'hidden God' behind the image of the world named איש for this mystical understanding of the implication of his appearance on earth. Some notable passages drawn from Philo (and basically plundered from the old Vridar site):
Philo identified the Logos with the Heavenly Man — see below. Philo also describes the Logos as God’s partner in creation
Allegorical Interpretation 3, 96
Now, Bezaleel, being interpreted, means God in his shadow. But the shadow of God is his word, which he used like an instrument when he was making the world. And this shadow, and, as it were, model, is the archetype of other things. For, as God is himself the model of that image which he has now called a shadow, so also that image is the model of other things, as he showed when he commenced giving the law to the Israelites, and said, “And God made man according to the image of God.” . . . as the image was modelled according to God, and as man was modelled according to the image, which thus received the power and character of the model.
On the Migration of Abraham, 6
What, then, can it be except the Word, which is more ancient than all the things which were the objects of creation, and by means of which it is the Ruler of the universe, taking hold of it as a rudder, governs all things. And when he was fashioning the world, he used this as his instrument for the blameless argument of all the things which he was completing.
The Special Laws 1, 81
For if it was necessary to examine the mortal body of the priest that it ought not be imperfect through any misfortune, much more was it necessary to look into his immortal soul, which they say is fashioned in the form of the living God. Now the image of God is the Word, by which all the world was made. Logos is The Beginning, The Ruler of the Angels, the Name of God
On the Confusion of Tongues, 146
And even if there be not as yet any one who is worthy to be called a son of God, nevertheless let him labour earnestly to be adorned according to his first-born word, the eldest of his angels, as the great archangel of many names; for he is called, the authority, and the name of God, and the Word, and man according to God’s image, and he who sees Israel. Logos is first-born of God and the Heavenly Man As an emanation of God he is also God’s offspring, the first-born son of God. As such he is a kind of immortal heavenly man or the true father of men.
On Flight and Finding, 72
For, in fact, the one God alone is the sole Creator of the real man, who is the purest mind; but a plurality of workmen are the makers of that which is called man, the being compounded of external senses; for which reason the especial real man is spoken of with the article; for the words of Moses are, “The God made the man;” that is to say, he made that reason destitute of species and free from all admixture. But he speaks of man in general without the addition of the article; for the expression, “Let us make man,” shows that he means the being compounded of irrational and rational nature.
That the Worse is Wont to Attack the Better, 83
Therefore, the faculty which is common to us with the irrational animals, has blood for its essence. And it, having flowed from the rational fountain, is spirit, not air in motion, but rather a certain representation and character of the divine faculty which Moses calls by its proper name an image, showing by his language that God is the archetypal pattern of rational nature, and that man is the imitation of him, and the image formed after his model; not meaning by man that animal of a double nature, but the most excellent species of the soul which is called mind and reason. Questions and
Answers on Genesis, 1.4
What is the man who was created? And how is that man distinguished who was made after the image of God? (Ge 2:7). This man was created as perceptible to the senses, and in the similitude of a Being appreciable only by the intellect; but he who in respect of his form is intellectual and incorporeal, is the similitude of the archetypal model as to appearance, and he is the form of the principal character; but this is the word of God, the first beginning of all things, the original species or the archetypal idea, the first measure of the universe. Moreover, that man who was to be created as a vessel is formed by a potter, was formed out of dust and clay as far as his body was concerned; but he received his soul by God breathing the breath of life into his face, so that the temperament of his nature was combined of what was corruptible and of what was incorruptible. But the other man, he who is only so in form, is found to be unalloyed without any mixture proceeding from an invisible, simple, and transparent nature.
On the Confusion of Tongues, 41
In reference to which I admire those who say, “We are all one man’s sons, we are men of Peace,” because of their well-adapted agreement; since how, I should say, could you, O excellent men, avoid being grieved at war, and delighted in peace, being the sons of one and the same father, and he not mortal but immortal, the man of God, who being the reason of the everlasting God, is of necessity himself also immortal?
Who is the Heir of Divine Things? 231
one of them being the archetypal pattern and above us, and the other being the copy of the former and abiding among us. And Moses calls the one which is above us the image of God, and the one which abides among us as the impression of that image, “For,” says he, “God made man,” not an image, “but after that Image.” So that the mind which is in each of us, which is in reality and truth the man, is a third image proceeding from the Creator. But the intermediate one is a model of the one and a copy of the other.
Allegorical Interpretation, 1, 31, 53, 55
“And God created man, taking a lump of clay from the earth, and breathed into his face the breath of life: and man became a living soul.” The races of men are twofold; for one is the heavenly man, and the other the earthly man. Now the heavenly man, as being born in the image of God, has no participation in any corruptible or earthlike essence. But the earthly man is made of loose material, which he calls a lump of clay. On which account he says, not that the heavenly man was made, but that he was fashioned according to the image of God; but the earthly man he calls a thing made, and not begotten by the maker.
“And the man whom he had formed,” Moses says, “God placed in the Paradise,” for the present only. Who, then, is he in reference to whom he subsequently says that “The Lord God took the man whom he had formed, and placed him in the Paradise to cultivate it and to guard It.” Must not this man who was created according to the image and idea of God have been a different man from the other, so that two men must have been introduced into the Paradise together, the one a factitious man, and the other modelled after the image of God?
Therefore, he calls that man whom he only places in Paradise, factitious; but him whom he appoints to be its cultivator and guardian he calls not factitious, but “the man whom he had made.” And him he takes, but the other he casts out. And him whom he takes he thinks worthy of three things, of which goodness of nature especially consists: namely, expertness, perseverance, and memory. Now, expertness is his position in Paradise; memory is the guarding and preservation of holy opinions; perseverance is the effecting of what is good, the performance of virtuous actions. But the factitious mind neither remembers what is good, nor does it, but is only expert, and nothing more; on which account, after it has been placed in Paradise, in a short time afterwards it runs away, and is cast out
I don't think it is necessary to do into great detail regarding the Philonic conception here other than to say that Christianity obviously borrowed his understanding of being directly made after the 'image of God.' This leads to what Philo references as 'perfection' (= the 'perfect man' in Marcionite/Pauline thought). Even thought Philo explicitly denies the understanding that the God behind the image was anthropomorphic, the Christian god is living proof that this interpretation wasn't always shared. Clearly Jacob 'seeing' God turns him into (or 'made after' the image) of God = איש.
This is what I believe is behind the apparently unworkable etymology of 'Israel' as 'a man seeing God.' It is a description of the process of initiation rather than an actually etymology. In other words, the God who is איש is 'seen' by the man made after Adam and the earthly man becomes transformed into the heavenly man who is איש.
