What does threescore and ten mean in the Bible?
Score The term "threescore and ten" is limited to the King James Version, simply because the term is an old English term. In the past the number twenty was referred to as one "score." Thus "threescore and ten" was 3 times 20 plus 10, or 70.
There is a common phase nowadays that "we are all living longer today". It is amazing to reflect on the fact that Moses wrote that we should live to 70-80 in this Psalm (90:10) some 3,500 years ago!
In Moses day, life expectancy for an Egyptian was around 45. At the same time the Hebrews were living to over 70, which is the average life expectancy of a man living in the UK today! Sadly, even today, due to the ravages of diseases such as AIDS in some African countries like Botswana, average life expectancy is only 41!
Why did they live longer back then?
The Hebrews were kept clean physically, morally and spiritually because they were obedient to God's laws, even though they did not fully understand why, they were still obedient. Jehovah's Law protected and guided the Israelites in every facet of life. For example, the regulations on diet, hygiene, and quarantine spared them from many of the diseases that ravaged other nations. Only after the discovery of bacteria in the 19th century did science begin to catch up with God's Law.
In England just over 100 years ago, a surgeon would move from handling a disease ridden corpse in the mortuary to operating on a live subject, using the same instruments and without even washing his hands! He didn't know about bacteria or cross infection, but 3,500 years ago the law said something very different in Numbers 19:11-16.
The Law of Moses also contained concepts of hygiene and disease control, such as the quarantining of sick people and the disposal of human waste, that harmonize with current science. (Deuteronomy 23:13, Leviticus 13:1-59; 14:38, 46;) This is remarkable considering that much of Egyptian medicine in Moses' day was a dangerous mixture of quackery and superstition. In developing lands today, millions could be spared from disease and premature death if the standards of hygiene taught by Moses were practiced.
As an aside, US President Lincoln's famous Gettysburg Address begins with Four score and.....