'Seventy' in the Bible

in the first year of his reign I, Daniel, came to understand from the sacred books that, according to the word of the LORD disclosed to the prophet Jeremiah, the years for the fulfilling of the desolation of Jerusalem were seventy in number.

"Seventy weeks have been determined concerning your people and your holy city to put an end to rebellion, to bring sin to completion, to atone for iniquity, to bring in perpetual righteousness, to seal up the prophetic vision, and to anoint a most holy place.