Understood by books; by sacred books, both of Jeremiah the prophet, Jeremiah 25:11,12 Jeremiah 29:10; so also the Pentateuch, which he had, as is plain, Daniel 9:10-13, &c.; by which we see this great prophet did not disdain to study the word of God, and the state of the church of God, though he had the converse and revelation of angels, and though he was in a heathen court, and in high office, which required great attendance. That he would accomplish seventy years in the desolations of Jerusalem: see Jeremiah 7:3,1 Jeremiah 22:5 25:18.
Related Commentaries of Daniel 9:2
Daniel 9:2
2 In the first year of his reign I Daniel understood by books the number of the years, whereof the word of the LORD came to Jeremiah the prophet, that he would accomplish seventy years in the desolations of Jerusalem.