Psalms 90:10
10 The daysa 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.
Psa. 90:10. Bedford's Scripture Chronology, p. 395. When God had positively declared that the Israelites should wander forty years in the wilderness, and that all of them except Joshua and Caleb should die there; and when he did thus cut short the age of man, to what it is at this time, then Moses penned a melancholy psalm, in which he tells us how they were consumed by God's anger for their impieties, and how man's age is come to seventy or eighty years, after which there is only labor and sorrow, instead of those hundreds that they lived before.
Here we may observe, that as sin at first brought death into the world, so sin did afterwards shorten the age of man before the flood: the patriarchs lived almost to a thousand years. But the sin which brought the flood, took away one half of man's age, so that they who were born afterwards never attained to the age of five hundred. At the confusion of Babylon it was shortened again in the same manner, so that none born after that time lived up to two hundred and fifty, as it is easy to observe by computing their ages. After the death of the patriarchs, when the true worship of God was very much declined in their families, and the rest of mankind were overrun with superstition and idolatry, the life of man was shortened again, so that we read of none born since, who exceeded a hundred and five and twenty; neither did the ages of men stand at that measure, but at the frequent murmurings and provokings of God in the wilderness, a third part more, or thereabouts, were cut off from the age of man, and the common limit of man's life was brought to seventy or eighty years, or thereabouts, or more particularly to eighty-three or eighty-four years, which very few exceeded, and which Moses speaks of in the before-mentioned psalm, composed upon that occasion. And though the sins of mankind have been very great and universal since that time, yet the age of man's life has not been shortened any more, because a shorter space would hardly have been sufficient for the finding out and improvement of arts and sciences, as well as for other reasons.
Psa. 91:11