The Bible interprets itself by comparing scripture with scripture. A key is always to look for Jesus first.  Psalm 45:6-7 are quoted in Hebrews 1:8-9 and applied to Jesus. “But unto the Son he saith, ‘Thy throne, O God, is for ever and ever: a scepter of righteousness is the scepter 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.’” 

Also the phrase “grace is poured into thy lips” (Psalm 45:2) is indirectly referred to in Luke 4:22 “And all bare him witness, and wondered at the gracious words which proceeded out of his mouth….”

King Jesus, His thousand year Kingdom, and His Bride are prophetically and poetically described throughout this Psalm. Verses 3-8 speak of the greatness of his kingdom.  Arrows and a sword are symbolic pictures of the power of truth, righteousness and meekness. The results of His kingdom will be to teach the people “terrible things” or a better translation would be tremendous, wonderful, or awesome. Once the people learn they will “fall under thee” that is submit to Christ’s rule. (verse 5)   

Philippians 2:10, 11 has a similar thought “…at the name of Jesus every knee should bow, of things in heaven, and things in earth, and things under the earth; And that every tongue should confess that Jesus Christ is Lord…” (see also 1 Corinthians 15:24, 25)

Verses 9-15 refer to the wonderful marriage of King Jesus. This imagery is in many places in the New Testament. (Matthew 22:1-10; 25:1-13, Ephesians 5:23-33) Revelation has several references to the bride of Christ especially 19:7,8 “…the marriage of the Lamb is come, and his wife hath made herself ready…she should be arrayed in fine linen, clean and white: for the fine linen is the righteousness of saints.”

In Psalm 45, the bride of Christ is described as forgetting her own people and her father’s house. Jesus explains the terms of discipleship, putting spiritual interest and relationships first, in Matthew 12:48-50, “Who is my mother? and who are my brethren?  And he stretched forth his hand toward his disciples, …whosoever shall do the will of my Father which is in heaven, the same is my brother, and sister, and mother.” Psalm 45 goes on to describe the beautiful character of the bride of Christ as her beauty within.

The virgins who follow the bride (45:14) are a secondary class of Christian described as foolish virgins. (Matthew 25:1-13) Though virgins (faithful to Christ and separate from the world) they are not as zealous as the wise virgins. A less than full reward is implied by John in 2 John 1:8 (ESV), “Watch yourselves, so that you may not lose what we have worked for, but may win a full reward.”

The King’s palace (45:15) is similar to John 14:2, 3 “In my Father's house are many mansions:…I go to prepare a place for you.  And if I go and prepare a place for you, I will come again, and receive you unto myself…”