Daniel understood from Jeremiah’s writings that the desolation of Jerusalem would last seventy years. He turned to God in prayer with confession and pleas for mercy concerning Jerusalem and the sanctuary. Daniel 9:2–3
Daniel dates his actions to the first year of Darius’s rule over the former Babylonian realm. During that year he studies “the books” and recognizes, from Jeremiah’s prophecy, that Jerusalem’s ruined condition was set to last seventy years. This scene opens the prayer-and-vision unit of Daniel 9. After earlier narratives about life under foreign courts and earlier visions about empires, the book now shows Daniel responding to Scripture itself. The story moves from a dated setting to Daniel’s understanding, then to his chosen response.
Daniel 9:1–3 presents a simple movement: a dated historical setting, Daniel’s reading of written prophecy, and Daniel’s deliberate turn to prayer.
A careful answer keeps the immediate passage, the book's argument, and the whole-Bible storyline together, so the question is answered in context instead of as a detached idea.
Start with Daniel 9:2-3, then read the surrounding section so the answer stays connected to the passage's flow.
2in the first year of his reign I, Daniel, understood by the books the number of the years whereof the word of Yahweh came to Jeremiah the prophet, for the accomplishing of the desolations of Jerusalem, even seventy years.
3I set my face to the Lord God, to seek by prayer and petitions, with fasting and sackcloth and ashes.