Daniel's Prayer for His People

91 In the first year of Darius the son of Ahasuerus, of the seed of the Medes, who was made king over the realm of the Chaldeans, 2 in the first year of his reign I, Daniel, understood by the books the number of the years about which the word of Yahweh came to Jeremiah the prophet, for the accomplishing of the desolations of Jerusalem, even 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.