Trinitarian Passages in Psalm 45

6 Your (the Son’s) throne, O God (the Son), is forever and ever. You (the Son) rule as a King with a righteous scepter.

7 You (the Son) love righteousness and hate wickedness, that is why God (the Father), Your (the Son) God (the Father), has anointed You with the Oil of Joy (the Holy Spirit) above Your companions.

See also Hebrews 1:8-9