One day Dogen instructed,

A layperson said, “A treasure is an enemy which harms one’s life. This has happened in the past, and it happens in the present as well.”  This is a reference to the person in the following story.  

Once there was a man who had a beautiful wife. A man who had power commanded the man to give him the woman. The husband was reluctant to give up his wife. Finally, the powerful man raised his troops and surrounded the house.  

When the wife was about to be taken away, her husband said, “I will give up my life for you.”  

His wife replied, “I will also give my life for you.”  

Saying this, she jumped from a lofty building and killed herself. Later the husband who failed to die told the story (from Shobogenzo Zuimonki, Book 5, Chapter 3)

Such a sad little story.  The wife's beauty was the man's treasure but also his enemy, as her beauty was coveted and sought after by others.   When those envious of his treasure were closing in, the man declared that he was ready to die for his wife, but his wife loved him very much and to save his life, she took her own. There's an almost Shakespearean level of tragedy in that O. Henry-like tale.

A treasure is an enemy which harms one's life.  Too much wealth, too much beauty, too much intelligence,  and even too much happiness all work like this.  The more of our treasure that we have, whatever it may be, the more we want to protect it.  And the more we want to protect it, the more we remove ourselves from others, and even from our own selves.  And we also suffer from the loss of the treasure, or even the thought of losing our treasure.

Better to have just enough, but never too much.