In the long-lived patriarchal age a generation seems to have been computed at 100 years, (Genesis 15:16) comp. Genesis15:13 and Eccl 12:40 But subsequently the reckoning was the same which has been adopted by modern civilized nations, viz. from thirty to forty years (Job 42:16) (Generation is also used to signify the men of an age or time, as contemporaries, (Genesis 6:9; Isaiah 53:8) posterity, especially in legal formulae, (Leviticus 3:17) etc.; fathers, or ancestors. (Psalms 49:19)
GENERATION
Meaning of GENERATION in English
Smith's Bible English dictionary. Английский библейский словарь Смита. 2012