The vision in chapter9 came after Daniel had been praying and fasting ( Daniel 9:3). The vision that follows also came to him after he had been mourning, fasting, and undoubtedly praying, for three weeks (cf. Daniel 1:11-13). Obviously these were literal weeks of days. Evidently, the previous revelations from God, and the welfare of the Jews-who had returned to Palestine but were encountering opposition, were the reasons for Daniel"s grave concern (cf. Ezra 4:1-5; Ezra 4:24; Philippians 4:6-7). Even though many Israelites were returning to Palestine, God had already revealed that they would experience trouble there. [source][source][source]