In an evening talk, Dogen said,
An ancient sage remarked, “If I learned the Way in the morning, I wouldn’t mind dying in the evening.” Students of the Way should have this same attitude. During aeons of life-and-death, how many times have we been born and have we died in vain? If we do not save ourselves, when, by rare chance, we have been born [in a human body] and are able to encounter the buddha-dharma, when will we (be able to save ourselves)? Even though we might cherish our body and hold it dear, we cannot keep it forever. Abandoning our life which we must leave behind sooner or later, if only for a day or a few moments for the sake of the buddha-dharma, will surely be the cause of eternal happiness.
It is regrettable to spend our days and nights vainly thinking of our livelihood tomorrow without casting aside the world which should be cast aside, without practicing the Way which should be practiced. Just make up your mind to learn the Way and die today. If you don’t have the materials to keep you alive until tomorrow it doesn’t matter if you die of cold or hunger. First of all, arouse such resolution. In doing so you will be able to practice the Way without fail.
Without this sort of aspiration, you will be unable to attain the Way regardless of how many millions of years or thousand times of life-and-death you practice. If you ostensibly continue practicing the buddha-dharma but secretly worry about such things as clothing for winter or summer and livelihood for tomorrow or the next year, then despite the appearance of learning the Way opposed to the ordinary world (it is equally useless). There could be such a person, but as far as I know such an attitude cannot be in accordance with the teaching of the buddhas and patriarchs.