Daniel's Prayer for His People

91 In the first year of Darius son of Xerxes[1] (a Mede by descent), who was made ruler over the Babylonian[2] kingdom- 2 in the first year of his reign, I, Daniel, understood from the Scriptures, according to the word of the Lord given to Jeremiah the prophet, that the desolation of Jerusalem would last seventy years.

Matthew Henry's Commentary on Daniel 9:1-2

Commentary on Daniel 9:1-3

(Read Daniel 9:1-3)

Daniel learned from the books of the prophets, especially from Jeremiah, that the desolation of Jerusalem would continue seventy years, which were drawing to a close. God's promises are to encourage our prayers, not to make them needless; and when we see the performance of them approaching, we should more earnestly plead them with God.