I wanted to continue to think about some of the stranger aspects of ancient Christian Christology, especially as it pertains to the Son's preincarnate existence in Ancient Israel. The story begins really with Justin Martyr who in his 1st Apology and especially in the Dialogue with Trypho seeks to establish that every time anyone ever claimed to see God in Israel's scriptures, they saw the Son, the Logos. While on the one hand, this helps to relieve some of the more embarrassing anthropomorphisms of the Bible by attributing them to God's manifest aspect - the Son (the image of the invisible God in Colossians 1) - on the other hand, Justin's blanket identification of the Son with all theophanies has further consequences since not all of the theophanies of the Bible are anthropomorphic.
In his First Apology 62-63, Justin uses Moses as the prototypical prophet, often called the “first prophet” throughout, both chronologically and in importance. He argues that one cannot maintain that Moses saw God the Father, but only God the Son, playing Exodus 3:6 – where God appears to Moses in the bush – and Matthew 11:27 – where none can know the Father but the Son – off one another. The Son is called Word (λόγος), Angel (ἄγγελος) which he uses interchangeably with “in the image of the bodiless” “in bodiless image” (ἐν εἰκόνι ἀσωμάτῳ; 63.10, 16), and Apostle (άπόστολος) (62.9-10; cf. Hebrews 3). The preincarnate Christ does not just appear in the fire, however, but as the fire, or literally “in the image of fire” (ἐν ἰδέᾳ πυρὸς ἐκ βάτου; 62.3; 63.10) or “the form of fire” (διὰ τῆς τοῦ πυρὸς μορφῆς); he is polymorphic, appearing here as fire, elsewhere as an angel, and finally through the incarnation as human (ἄνθρωπος). Justin summarizes:
Καὶ πρότερον <δὴ> διὰ τῆς τοῦ πυρὸς μορφῆς καὶ είκόνος άσωμάτου τῷ Μωσεῖ καὶ τοῖς ἑτέροις προφήταις ἐφάνη. νῦν δ’ ἐν χρόνοις τῆς ὑμετέρας άρχῆς, ὡς προείπομεν, διὰ παρθένου ἄνθρωπος γενόμενος κατὰ τὴν τοῦ πατρὸς βουλὴν ὑπὲρ σωτερίας τῶν πιστευόντςν αὐτῷ καὶ ἐξουθενηθῆναι καὶ παθεῖν ὑμέμεινεν, ἵνα ἀποθανὼν καὶ ἀναστὰς νικήσῃ τὸν θάνατον. (63.16)
And he formerly appeared through the form of fire and a bodiless image to Moses and the other prophets; but now in the times of your reign, as, we have said, having become a human by a virgin according to the counsel of the father on behalf of the salvation of those who believe in him and he endured to be made nothing and to suffer so that, dying and rising, he would defeat death.
In order to tighten the connection between old and new covenants by making Christ the proclaimer of both, it at first seems that Justin is diluting the singularity of the incarnation, yet the frequent usage of “bodiless image” when these appearances are at their most anthropomorphic (e.g., in the appearance as an “angel”) emphasizes the contrast of previous bodiless theophanies, which have a strangely docetic feel to them, to Moses and the prophets and the decidedly bodily emphasis on the incarnation, which leads to salvation through death and resurrection. But perhaps that is why he also emphasizes the Son's pyromorphism - he appears in the past as fire and later as human.
Justin is more programmatic in the Dialogue with Trypho 127.
Οὔτε οὖν Ἀβραὰμ οὔτε Ἰσαὰκ οὔτε Ἰακὼβ οὔτε ἄλλος ἀνθρώπων εἶδε τὸν πατέρα καὶ ἄρρητον κύριον τῶν πάντων ἁπλῶς αὐτοῦ τοῦ Χριστοῦ, ἀλλ’ ἐκεῖνον τὸν κατὰ βουλὴν τὴν ἐκείνου καὶ θεόν, υἱὸν ὄντα αὐτου, καὶ ἄγγελον ἐκ τοῦ ὑπερτεῖν τῇ γνώμῃ αὐτοῦ· ὃν καὶ ἄνθρωπον γεννηθῆναι διὰ τῆς παρθένου βεβούληται, ὃς καὶ πῦρ ποτε γ´γεονε τῇ πρὸς μωσέα ὁμιλία τῇ ἀπὸ τῆς βάτου
Therefore neither Abraham, nor Isaac, nor Jacob, nor any other man, saw the Father and ineffable Lord of all, and also of Christ, but saw Him who was according to his will his son, being God, and the Angel because he ministered to his will; whom also it pleased him to be born man by the virgin; and also was fire when he conversed with Moses from the bush.Not just individual theophanies, therefore, were the preincarnate Son, but all were. He appears as angel, human, fire, and cloud. He is more straightforward here - it is no longer the "image of fire" or the "form of fire"; but the Son was fire. If no one can see the Father except the Son (Matt 11:27; John 1:17-18), if the Son is the image of the invisible God (Col 1:15), then the Lord, the angel of the Lord, God’s visible – yet intense – Glory, etc., in the Old Testament was none other than Christ. With this simple maneuver, Justin transformed the Jewish scriptures into a Christian revelation, in which Christ reveals to Moses and the prophets coded messages about Christ.
In Justin's wake, the second and third century apologists can just assume his argument that all theophany is really Christophany, and so the Son, whose greatest significance is God made human will be occasionally non-anthropomorphic - that is, pyromorphic and nebulomorphic (?) - in Irenaeus, Against Heresies 4.7.4; 4.10.1; cf. 4.33.11; see further Clement of Alexandria, Prot. 1.