זה ספר תולדות אדם, “this is a record of human history.” This is a reference to the various children mentioned in the remainder of the chapter. Beyond this, it is reasonable to consider the entire Torah a record of mankind’s history (up to the end of Moses’ life) and this is the reason why the Torah here did not choose to write אלה תולדות אדם, as it did on other occasions.

ויולד בדמותו, בצלמו, “he begat in his likeness and in his image.” It is a well known fact that all the children born to man resemble their parents in large measure. So what did the Torah tell us here that we did not already know? The fact is that first man, not born of woman had been fashioned by G’d and been described by Him as being בצלם אלוקים. We might have thought that this distinction applied only to the first human being, the one who was the direct product of G’d’s handiwork. The Torah tells us here that this distinction was passed on throughout the generations. No mention was made of this distinction when Kayin and Hevel were born, as the Torah did not want to dwell on these two (whose descendants ceased at the time of the deluge) Seeing that Noach and his family were descendants of Sheth, it was important to inform us that their exteriors also reflected their G’dliness. According to the Midrash, the Torah mentions the fact that Adam reproduced in his own image to alert us to the fact that seminal emissions during the one hundred and thirty years before the birth of Sheth had resulted in the formation of שדים ומזיקים, spiritually and physically harmful creatures.

ויהיו ימי אדם, “Adam’s lifespan amounted to, etc.” Seeing these early generations lived for so many years when compared to the lifespan of man in times after the deluge, the Torah adopted a method of telling us about their inordinately longs life spans immediately after reporting that these people fathered their first children at an age when most of us nowadays have long been buried already. By choosing the method adopted here, the Torah explains why these people married (relatively speaking) so late and did not start a family sooner. Seeing that original man had been fashioned by the Creator Himself, he had been endowed with a more perfect body, enabling him and the first few generations after him, to live longer than usual lives in spite of death having been decreed for the species as a whole. Due to the gradual spiritual corruption of mankind, their bodies were affected negatively also, so that immediately after the deluge the average life span had already shrunk to less that half of what it had been prior to the deluge. After the dispersal as a result of the building of the Tower, the life expectancy shrank further, not least because suddenly man had to adjust to climactic changes during the year in the locations to which they had been dispersed. It would seem that the lifetime of people other than the patriarchs had already shrunk to an average of seventy years, (the immediate offspring of Avraham, Yitzchok and Yaakov excepted) We know this from Moses’ prayer recorded in the Book of Psalms, 90,10, where he describes this number as a “normal.” lifespan. The fact that Pharaoh was dumbfounded when Yaakov told him that he was already 130 years old, seems to support this theory. (Genesis 47,9) Maimonides writes that all the people mentioned in the Torah as having attained such longevity were exceptions and that is why their individual life spans have been mentioned. He credits their exceptional longevity to their having been very careful with their diets, foregoing foods which are basically life-shortening. Anyone not mentioned specifically lived a normal lifespan. Nachmanides already questions Maimonides’ opinion, citing the fact that the people mentioned as having lived for so long were not prophets so that G’d should have performed a miracle [I might add that Chanoch, (5,23) whom the Torah described as loyal to G’d, ”walking with Him,” (5,24) lived far fewer years than his not so righteous contemporaries Ed.] Also, why, according to Maimonides, would the נפילים, corrupt individuals, be granted such long lives as the Torah testified that the spies in Moses’ time had encountered?