The final death that happens once and for all means that the whole body is destroyed; but what happens all at once in the entire body when a man dies is also taking place throughout the body during life, in a piecemeal process. Man excretes not only through his organs of excretion, the urine, feces, sweat, but in other ways as well. Just think what your head would look like if you never had your hair cut! Something is excreted there, too.
And think of the claws you’d have if you never cut your nails! But not only that: man is all the time sloughing off his skin — he just doesn’t notice it.
Man is casting off substance all the time. In the case of the urine and feces the process is not very significant, because for the most part these simply contain what has been eaten, material that has not gone into the whole body, whereas what is excreted in the nails has gone through the whole body.
Suppose you take your scissors and cut a fingernail. What you now cut away, you took in, you ate seven or eight years ago. What you ate went into the blood and nerves and passed through the whole body. It needed seven or eight years to do that. Now you cut it away. Just think of the body you have today, the body in which you are sitting there. If you had sat there seven or eight years ago, it would have been in quite another body! The body you had then has been cast away, has been sweated away, has been cut away with the nails, cut away with the hair. The entire body as it once was, has gone — with the exception of the bones and the like — and within a period of seven or eight years has been entirely renewed.
Source: Rudolf Steiner – GA 354 –Evolution, Earth, Man: Lecture XIV – Dornach, September 24,1924