The first verse says, "The Song of songs, which is Solomon’s." Solomon wrote a thousand five songs (1 Kings 4:32). Of all his songs, this is the best and most precious one. Consequently, it is called the "Song of songs." The inner sanctuary is the Holy of Holies. The Lord Jesus is the King of kings and Lord of lords. This is the Song of songs. The book of Ecclesiastes speaks of vanity of vanities, whereas this book is the Song of songs.
This Song is in contrast with Ecclesiastes. Ecclesiastes speaks of an unsettled life, but this Song speaks of the rest after being unsettled. Ecclesiastes tells us that man cannot be satisfied with knowledge, but this Song tells us that man can only be satisfied by love. Ecclesiastes tells us about the pursuit under the sun, but this Song tells us about the pursuit of Christ. In Ecclesiastes the object that is being sought after is a wrong one, and the way is the wrong way. The result is vanity of vanities. In the Song of songs the object that is being sought after is the right one, and the way is the right way. The result is the right end.
(The Song of Songs, Chapter 0, by Watchman Nee)