It is more useful to read the Biblical text than commentaries on the text. However, commentaries can be very helpful for some of the texts, with the book of Jeremiah being a good example. Here’s a bit from the introductory section of J. A. Thompson’s commentary The Book of Jeremiah.
The prophets were not merely religious teachers or philosophers in the abstract, but saw themselves as the messengers of God commissioned to convey to the people of their own day the word that God had given them. They had a specific message to a specific people at a specific point in history. It was a message which would interpret the events through which their people were passing, or would pass, in the light of the demands and promises which God had given to their eole. Clearly, this dimension of a prophet’s ministry cannot be understood unless the historical background of his times is known.
The book of Jeremiah makes contact with historical events at many points. In many cases precise dates and otherwise known events are referred to. It was Jeremiah’s responsibility to proclaim a message about nations and kingdoms, “to pluck up and to break down, to destroy and to overthrow to build and to plant” (1:10). It was an age of crises. As Jeremiah began to preach, the Assyrian empire was in decay. At the collapse of Assyria, Egypt, and then Babylon, the kingdom of the Medes stood waiting to pick the spoils of war. Judah herself was caught up in the drama. To begin she was nominally a vassal of Assyria, then for a brief period independent, then a vassal of Egypt, and finally a vassal of Babylon, under whom Judah lost even her identity as a nation when Nebuchadrezzar took her king into exile and destroyed her city and temple. Jeremiah lived through all this, and much of the drama of those years is reflected in his book. It was a time of agony for Jeremiah himself and for his people. Anyone who attempts to read the book without knowing something of the times will be more bewildered than ever. The arrangement of the book is complex and the variety of materials is considerable. If one lacks any sort of historical anchorage as well, the book is a bewildering one.
We have a good deal of biblical material to help fill in some of the historical background to Jeremiah. There are the narratives in 2K. 2125, supplemented by the account in 2 Chr. 3336. Further material is available from the books of contemporary prophets Zephaniah, Nahum, Habakkuk, and Ezekiel. Then we have the Babylonian Chronicle for the years 617 BC on. Archeological discoveries of one kind and another, including some small but important written item, add to our knowledge. There are, alas, many gaps in our knowledge in spite of these sources, but such information as we have enables us to make some headway in understanding the period.