This metaphor can be understood as a person's inner needs to develop in a balanced way like a tree. Although people are eager to develop upward and pursue higher realm and achievements, they should also take root down like roots, go deep into their hearts and essence, and explore and understand their feelings, values and needs. Only on this basis can we better face the challenges and opportunities in life and realize our own growth and development.
In addition, this metaphor also implies some helplessness and complexity in life. Just as the root of a tree must be rooted in the soil, although it may be restricted and bound, it is also the basis for the survival and growth of a tree. Similarly, a person's heart also needs to accept his own limitations and dark side, so as to better understand himself and pursue higher goals.
In a word, this sentence is a kind of enlightenment and warning, reminding people to balance their internal and external development like a tree, and at the same time accept their limitations and complexity in order to realize their own growth and happiness.