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What was the average length of each generation from Abraham to David?
Matthew and Luke: Seventy years.
Seventy years is said to constitute the natural life of man. According to these Evangelists Christ’s Pre-Davidic ancestors only reached maturity at seventy. How slow was man’s development then—a babe in his mother’s arms at twenty; a playful child at forty; at sixty an ardent youth wooing a blushing maiden of half a hundred years; at three score years and ten a fond young father rejoicing at the birth of his first-born!