Komentaryo sa Levitico 15:16: Ibn Ezra, Rabbeinu Bahya, Chizkuni & Rav Hirsch

a man from whom semen spills out involuntarily

ורחץ במים את כל בשרו, “he must wash his entire body with water.” This is the only time in connection with the legislation of ritual impurity that the Torah speaks of washing “the entire body.” Even when purification from more severe levels of ritual impurity is discussed, such as the person suffering a discharge, the Torah did not demand that “the whole body” be washed. The reason for all this may have to do with the four basic raw materials man is made of, i.e. fire, spirit (wind), water and dust. This was not the order in which these elements appear in the report of the creation in Genesis where the first element mentioned is the spirit (רוח) in Genesis 1,1, followed by water and fire and dust (earth).

In the Sefer Yetzira, (oldest kabbalistic text) air-(רוח)- fire-water are listed as the three “mothers,” so-called because they are like mothers to all that is found in the universe. These three elements are perceived as “descended” from the other, i.e. air begets water and water begets fire. This view is supported by verses from the Scriptures, of course. When the Torah writes in Genesis 1,2: בהו, וחושך; this means that fire is descended from water. The words ורוח אלו-הים מרחפת על פני המים mean that the water is “descended” from the element רוח, “air or spirit.” This is the reason why in our daily prayers we refer to the sequence משיב הרוח ומוריד הגשם, “who makes the air blow and makes the rain descend.” Support for the statement that fire is “descended” from water comes from the scientific fact that fire is [or at least may be Ed.] extracted from water. (compare Talmud Beytzah Mishnah folio 33 that “on the festival it is forbidden to extract fire from the water.”) [apparently experiments were conducted with glass bottles filled with water being exposed to intense sunlight. After a while, due to the water having become overheated, the glass burst into flames. quoted by Rashi. Ed.] Dust, i.e. earth is “descended” from fire. The reference is to the fertiliser left behind after something has been burned up. [Dust or earth in this instance refers to the earth and its ability to produce crops, etc. Perhaps the earth thrown up as volcanic ash is the best example of fire “producing” fertile earth. Ed.]
When these three elements surface as part of a human being they have been metamorphosed, the white part of man corresponds to the element water; the red part of man corresponds to the element fire; the black part of man corresponds to the element dust=earth. The element רוח, “spirit,” which is a fundamental part of man is the basic element and dominates all the other elements of which he is composed.