Matthew Bates (Birth of the Trinity) points to Hebrews 1:8-9’s quotation of Psalm 45 as an example of “prosopological” interpretation of the Old Testament. The Logos or Spirit speaks in the persona (prosopon) of the poet of the Psalm, and the interaction described in the Psalm is intra-divine conversation.
As Bates summarizes, “A person designated ‘God’ is directly addressed in the psalm. This person possesses the royal scepter, rules with justice, and most crucially has been anointed by a second person called ‘your God’ in the text. Since the person designated ‘your God’ anoints the other person called ‘God,’ and the action is not reflexive, two persons both called ‘God’ are necessarily present in the text. Moreover, the verbal action of anointing (echrisen), which the one labeled ‘your God’ undertakes and the one termed ‘God’ receives, is closely associated with the noun Christos. . . , which literally means ‘anointed one.’ For the early Christians, thus, the one doing the anointing in the text is God the Father and the one on whom the oil is poured is God the Son, the Christ, the anointed one” (164).
Bates points out that this is not seen as a “dialogue between the Father and the Son.” Instead, “the Son, the Christ, is being addressed theodramatically by some unidentified person who is speaking directly to the Son, while this mysterious speaker also describes the relational activities that characterize the Father and the Son” (164). Who is the poet-reporter of this interaction? Bates suggests that “the Holy Spirit, probably appearing here as a speaking theodramatic prosopon in the Spirit’s own right, is ultimately the one who called this anointed person ‘God’ in addition to the Father” (164). Thus, “it is likely that all three prosopa of what could later come to be termed the Trinity -Father, Son, and Spirit – were individually and distinctly found to be ‘God’ through a person-centered reading strategy” (165).
A gloss: If this is right, then the Spirit is the first-person speaker of the opening verses: “My heart overflows with a good theme, I am saying my made-thing to the King. My tongue is the pen of a ready writer” (v. 1). The Spirit is not only speaker here, but poet, a craftsman of words who produces “something made” to praise the king. That fits the personal profile of the Spirit – Creator, inspirer, maker, the Other who calls attention not to Himself but to the Son who glorifies the Father. In the inner life of the Trinity, there is the Anointed, the Anointed King, and the Court Poet who praises both.
This is what we learn when we listen to the Spirit who searches and reveals the deep things of God.