Read Psalm 45 at Bible Gateway.
This psalm forms the most unusual chiastic structure I have encountered yet in Scripture:
1a) Psa 45:1, The composition of praise to the King;
1b) Psa 45:2-9, The glory of the mighty King;
central axis) Psa 45:9, The King and Queen united;
2b) Psa 45:10-16, The beauty of the royal Bride;
2a) Psa 45:17, The memory and praise of the King forever.
This is a beautiful psalm prophesying of the King and Queen at their marriage supper. The King is, of course, Messiah Yeshua, and the Queen is His Bride, the ekklesia of believers! What is unusual about it, is that the B elements praising the glory of the King and the beauty of the Bride each form their own chiastic structures:
Psa 45:2-8, The glory of the mighty King:
1a) Psa 45:2, Grace poured upon the King’s lips;
1b) Psa 45:3-5, The King’s victory over His enemies;
central axis) Psa 45:6, Your throne, O God, is forever and ever;
2b) Psa 45:7a, The King loves righteousness and hates wickedness;
2a) Psa 45:7b-8, The anointing oil of gladness poured upon the King’s garments.
Psa 45:10-16, The beauty of the royal Bride:
1a) Psa 45:10, Forget your father’s house;
1b) Psa 45:11a, The King will greatly desire your beauty;
central axis) Psa 45:11b, Because He is your Lord, worship Him;
2b) Psa 45:13-15, The beauty of the bride in her robes;
2a) Psa 45:16, Instead of your fathers shall be your sons.
Moreover, within the stanzas praising the glory and beauty of the King and His Bride, there are even smaller structures. The kingdom of our Lord and His Messiah will come to pass upon this earth, His enemies will be defeated, His reign as King of kings and Lord of lords will be established, and He shall rule forever and ever, in grace, in glory, in might, in joy, in gladness, in righteousness, humility, and truth! He will marry His Bride, and the Queen will be united with Him!