Origen's Understanding of Psalm 45:6-7 (Contra Celsum 1.56)

But attend carefully to what follows, where He is called God: "For
Thy throne, O God, is for ever and ever: a sceptre of righteousness is
the sceptre of Thy kingdom. Thou hast loved righteousness, and hated
iniquity: therefore God, even Thy God, hath anointed Thee with the oil
of gladness above Thy fellows." And observe that the prophet, speaking
familiarly to God, whose "throne is for ever and ever," and "a sceptre
of righteousness the sceptre of His kingdom," says that this God has
been anointed by a God who was His God, and anointed, because more
than His fellows He had loved righteousness and hated iniquity. And I
remember that I pressed the Jew, who was deemed a learned man, very
hard with this passage; and he, being perplexed about it, gave such an
answer as was in keeping with his Judaistic views, saying that the
words, "Thy throne, O God, is for ever and ever: a sceptre of
righteousness is the sceptre of Thy kingdom," are spoken of the God of
all things; and these, "Thou hast loved righteousness and hated
iniquity, therefore Thy God hath anointed Thee," etc., refer to the
Messiah (Contra Celsum 1.56).

Πρόσχες δ' ἐπιμελῶς τοῖς ἑξῆς, ἔνθα θεὸς εἴρηται· «Ὁ θρόνος σου», γάρ φησιν, «ὁ θεός, εἰς τὸν αἰῶνα τοῦ αἰῶνος, ῥάβδος εὐθύτητος ἡ ῥάβδος τῆς βασιλείας σου. Ἠγάπησας δικαιοσύνην καὶ ἐμίσησας ἀνομίαν· διὰ τοῦτο ἔχρισέ σε ὁ θεὸς ὁ θεός σου ἔλαιον ἀγαλλιάσεως παρὰ τοὺς μετόχους σου.» Καὶ κατανόει ὅτι θεῷ ὁμιλῶν ὁ προφήτης, οὗ «ὁ θρόνος» ἐστὶν «εἰς τὸν αἰῶνα τοῦ αἰῶνος», καὶ «ῥάβδος εὐθύτητος ἡ ῥάβδος τῆς βασιλείας» αὐτοῦ, τοῦτον τὸν θεόν φησι κεχρῖσθαι ὑπὸ τοῦ θεοῦ, ὃς ἦν αὐτοῦ θεός· κεχρῖσθαι δέ, ἐπεὶ «παρὰ τοὺς μετόχους» αὐτοῦ οὗτος ἠγάπησε «δικαιοσύνην» καὶ ἐμίσησεν «ἀνομίαν». Καὶ μέμνημαί γε πάνυ θλίψας τὸν Ἰουδαῖον νομιζόμενον σοφὸν ἐκ τῆς λέξεως ταύτης· ὃς πρὸς αὐτὴν ἀπορῶν εἰπεῖν τὰ τῷ ἑαυτοῦ ἰουδαϊσμῷ ἀκόλουθα, εἶπε πρὸς μὲν τὸν τῶν ὅλων θεὸν εἰρῆσθαι τὸ «Ὁ θρόνος σου, ὁ θεός, εἰς τὸν αἰῶνα τοῦ αἰῶνος, ῥάβδος εὐθύτητος ἡ ῥάβδος τῆς βασιλείας σου», πρὸς δὲ τὸν Χριστὸν τὸ «Ἠγάπησας δικαιοσύνην καὶ ἐμίσησας ἀνομίαν· διὰ τοῦτο ἔχρισέ σε ὁ θεὸς ὁ θεός σου» καὶ τὰ ἑξῆς.]

See http://khazarzar.skeptik.net/books/origenes/cc/gr/