'Fulfill the Word of the Lord' in the Bible

To fulfill the word of the LORD by the mouth of Jeremiah, until the land had enjoyed her sabbaths: for as long as she lay desolate she kept sabbath, to fulfill seventy years.

Now in the first year of Cyrus king of Persia—in order to fulfill the word of the Lord by the mouth of Jeremiah—the Lord stirred up the spirit of Cyrus king of Persia, so that he sent a proclamation throughout his kingdom, and also put it in writing, saying,