Impermanence is swift; life-and-death is the great matter. This is what we see and hear about other: born in the morning, dead in the evening, the person we saw yesterday is no longer with us today. We see these facts with our eyes and we hear them with our ears.
Impermanence is truly the reality right in front of us. We need not wait for some teaching from others, or proof from some passage of scripture. Think deeply in your heart of the impermanence of the world. It is not a matter of meditating using some provisional method of contemplation. It is not a matter of fabricating in our heads that which does not really exist.
Though we expect to live for seventy or eighty years, we die when we must die. During our lifetime, though we may encounter sorrow, pleasure, love of our families, and hatred of our enemies, these are not worthy matters. We should spend our time letting go of such things.
Much more so for the aged whose lives are already more than half over. How many years still remain? Tonight or tomorrow we may contract some serious disease, or may have to endure such terrible pain as to be unable to distinguish east from west. Or we may be killed suddenly by some demon, encounter trouble with brigands, or be killed by some enemy. Everything is truly uncertain. Therefore, in such an unpredictable world, it is extremely foolish to waste time worrying about various ways of earning a living in order to postpone one’s death, uncertain as it is, to say nothing of plotting evil against others.
Impermanence is swift; life-and-death is the great matter. Our life is like a dream. Time passes swiftly. Our dewlike life easily disappears.
Since time waits for no one, try to do good for others as long as you are alive. (Based on passages from Dogen's Shobogenzo Zuimonki)