B'resheet (Gen) 6:1-4

In time, when men began to multiply on earth, and daughters were born to them, the sons of God saw that the daughters of men were attractive; and they took wives for themselves, whomever they chose. ADONAI said, “My Spirit will not live in human beings forever, for they too are flesh; therefore their life span is to be 120 years.” The N’filim were on the earth in those days, and also afterwards, when the sons of God came in to the daughters of men, and they bore children to them; these were the ancient heroes, men of renown. (Maftir)