The days of our years are threescore years and ten; and if by reason of strength they be fourscore years, yet is their strength labor and sorrow; for it is soon cut off, and we fly away (Psalm 90:10).
When Moses wrote these words, near the end of his life, he was 120 years old (Deuteronomy 34:7), but all the rest of the people of Israel (except Caleb and Joshua), who had been over 20 at the beginning of the 40-year wilderness wanderings, had died there (Numbers 14:28-34), and so there were no others over 60 years old.
In former days, men had lived much longer. Adam died at 930 and Noah at 950, but then Shem only lived to 600, and Abraham died at 175 years of age. Thus, the normal life span by Moses time was down to 70 or 80 years, and he prophesied that this would continue.
It is remarkable that, with all the increase in medical knowledge, this figure has stayed about the same, and there seems to be little the gerontologists can do to increase it.
Furthermore, the latter years are largely labor and sorrow, just as God told Adam when his sin brought Gods curse on the earth (Genesis 3:17-20). No matter how much we try to prolong our lives, we are soon cut off.
But then, we fly away! The soul/spirit complex of the Christian believer, released from its weary body, flies away to be with the Lord. Those left behind may sorrow, but to depart, and to be with Christ . . . is far better. The Christian may confidently say with Paul: For to me to live is Christ, and to die is gain (Philippians 1:23,21). In the meantime, as our time grows shorter, it is more important than ever that we walk in wisdom toward them that are without, redeeming the time (Colossians 4:5). So teach us to number our days, prayed Moses (and so should we), that we may apply our hearts unto wisdom (Psalm 90:12). HMM