The followings are the excerpts and my comments.
The Chinese, searching for a word that might translate shunyata, used the character for “sky.” All dharmas are empty like the sky—blue, beautiful, expansive, and always ready to receive a bird, a wind, a cloud, the sun, the moon, or an airplane.
I would say that "空" means "space" instead of “sky.” All dharmas (things = phenomena = objects of mind = perceptions) are, because space (空間) is. In other words, everything is empty of separate existence. Without space, nothing can exist.
All phenomena are products of dependent arising: that is the main point of the prajñaparamita teaching. This helps us to get in touch with the true nature of no birth/no death, no being/no non-being, etc., which is the true nature of all phenomena.
"Dependent arising", or "Interdependent co-arising" is the skillful means to transcend the duality. Because it is still based on the duality, it is still the ultimate truth in the historical dimension, or the phenomenal world. So, it is not the ultimate truth in the ultimate dimension (nirvana), or the noumenal world. Through "Interdependent co-arising", we can say that birth and death are two sides of the same coin but we can not say that there is no birth and no death. We can touch the true nature of reality only through the extinction of all notions, or nirvana.
This is a state of coolness, peace, and non-fear that can be experienced in this very life, in your own body and in your own five skandhas. It is nirvana.
Non-fear can be attained through the extinction of all notions, or nirvana. So, we need to understand that birth and death are nothing but notions and all notions are wrong. And nirvana means the ultimate dimension, or the noumenal world without space and time. So, only awareness, non-separate self, true self, the Dharma (cosmic) body, or the Buddha nature can dwell in nirvana. Non-separation, non-discrimination, non-duality, or the wholeness is the nature of the ultimate dimension.
Thích Nhất Hạnh