Samsara (the wheel of life and death) Nirvana (liberation from life and death)
If a person looks for buddha outside of life and death, that is like pointing a cart north and making for [the south country of] Etsu, or like facing south and hoping to see the North Star. It is to be amassing more and more causes of life and death, and to have utterly lost the way of liberation. When we understand that only life and death itself is nirvana, there is nothing to hate as life and death and nothing to aspire to as nirvana. Then, for the first time, the means exist to get free from life and death. To understand that we move from birth to death is a mistake. Birth is a state at one moment; it already has a past and will have a future. For this reason, it is said in the Buddha-Dharma that appearance is just nonappearance. Extinction also is a state at one moment; it too has a past and a future. This is why it is said that disappearance is just non-disappearance. In the time called “life,” there is nothing besides life. In the time called “death,” there is nothing besides death. Thus, when life comes it is just life, and when death comes it is just death; do not say, confronting them, that you will serve them, and do not wish for them.
This life and death is just the sacred life of buddha. If we hate it and want to get rid of it, that is just wanting to lose the sacred life of buddha. If we stick in it, if we attach to life and death, this also is to lose the sacred life of buddha.
Shobogenzo, Shoji, Gudo Nishijima & Mike Cross