This is an important chapter in that it evokes the feminine or yin (陰) aspect of the Dao, which complements its masculine or Yang (陽) aspect.
The spirit of the valley never dies;
It’s called the subtle and profound female.
The gateway to the subtle and profound female,
Is called the root of Heaven and Earth.
It’s continuous and everlasting;
No matter how much it’s used, it’s never exhausted.