Dogen Zenji's words are insanely difficult. It looks like a tanka phrase. While writing so that it can be read quickly and honestly, it actually explains a different dimension of Buddhism...
First, “revealing” means “clarifying.” In short, it means “enlightenment” and “enlightenment is important.” You're probably conscious of life and death at the beginning of Shushengi.
If you read volume 2 of Zuibunki flat, it says, “If you eat that snack, your life will end in a blink of an eye before you realize it, right? It can be read as “Be trained in Buddhism all along.” This is one way to read it. I guess they chose the words so they actually sounded like that. However, if you read it by linking it to Genzo's Life and Death Volume, you can see another way to read it...
Buddhism is selfless after all. I'm not there. There is no me who reincarnates. Since I'm not there, there is no such thing as this past life, this present life, and this next life. Originally, I realized that it wasn't there... that is selflessness and liberation. But nothing doesn't mean zero.
So what is nothing? There is no getting rid of my own fence. It doesn't erase me; it removes the boundary between here and here. What happens then? Just as the water in the faucet that was being held down with your finger spreads rapidly, it spreads out perfectly between the past, present, and future. That's none. Nothing is everything. Turn it all up and it's Buddha.
So time exists in the past, present, and future, but since there are no barriers between past present and future, there is no past present future. Similarly, I exist, but I don't exist.
At that time, Dogen Zenji said in Zuhonki, “Don't focus on one thing.” It's not “I'll realize it someday,” but “do what you need to do right now with all your heart and soul.” If I do zazen, I will disappear and I will become zazen. Since there is no barrier called zazen, it all goes well.
But if you think about zazen when eating, it becomes a delusion that the meal is neither rice nor zazen. That is hesitation and annoyance. When it's time to eat, it's just rice. I'm not there because it's just food. Since I'm not there, it all comes to a close. This is called just meditating. “Don't focus on one thing” means just meditating. This is now linked to the “big one character” in Denza lessons, and life and death come to be seen in a different way.
Well, to put it bluntly, don't do bad things, do each and every one of your lives carefully, and if you are kind to each other person, animal by animal, one by one, and living things, life and death are naturally revealed... it's impermanent, quick, life and death.