Answer
Many individuals interpret Genesis 6:3 as a 120-year age limit on humanity, “Then the Lord said, ‘My Spirit will not contend with man forever, for he is mortal; his days will be a hundred and twenty years.’” Nevertheless, Genesis chapter 11 documents several individuals surpassing the age of 120. Consequently, some construe Genesis 6:3 to imply that, as a general principle, individuals will no longer exceed 120 years of age. Following the flood, lifespans began to significantly decrease (compare Genesis 5 with Genesis 11) and eventually diminished to the point where very few individuals reached 120 years old. By the time of the Exodus, scarcely anyone survived to that age. Moses and Aaron lived to that age (Numbers 33:39;Deuteronomy 34:7), and Jehoiada the priest lived to 130 «But Jehoiada waxed old, and was full of days when he died; an hundred and thirty years old was he when he died. », (2 Chronicles 24:15). Therefore, 120 years was not a “hard” boundary; instead, it was close to the age that an exceptionally healthy and fortunate individual could anticipate surviving.
Nevertheless, another interpretation, which appears to align more closely with the context, is that Genesis 6:3 signifies God’s announcement that the flood would happen 120 years after His statement. The termination of humanity’s days refers to humanity itself being eradicated in the flood. Some challenge this interpretation because God instructed Noah to construct the ark when Noah was 500 years old in Genesis 5:32, and Noah was 600 years old when the flood arrived «And Noah was six hundred years old when the flood of waters was upon the earth. », (Genesis 7:6); only allowing 100 years oIf time, not 120 years. However, the timing of God’s pronouncement of Genesis 6:3 is not given. Further, Genesis 5:32 is not the time that God commanded Noah to build the Ark, but rather the age Noah was when he became the father of his three sons. It is perfectly plausible that God determined the flood to occur in 120 years and then waited several years before He commanded Noah to build the ark. Whatever the case, the 100 years between Genesis 5:32 and 7:6 in no way contradicts the 120 years mentioned in Genesis 6:3.
Several hundred years after the flood, Moses declared, “The length of our days is seventy years—or eighty, if we have the strength; yet their span is but trouble and sorrow, for they quickly pass, and we fly away” «The days of our years are threescore years and ten; And if by reason of strength they be fourscore years, Yet is their strength labour and sorrow; For it is soon cut off, and we fly away. », (Psalm 90:10). Neither Genesis 6:3 nor Psalm 90:10 are God-ordained age limits for humanity. Genesis 6:3 is a prediction of the timetable for the flood. Psalm 90:10 is simply stating that as a general rule, people live 70-80 years (which is still true today).