According to 2 Kings 24:3, the Babylonian Exile was God’s punishment upon the nation for the sins of Manasseh. In the thinking of ancient times, the righteousness or sin of a king was attributed also to the nation as a whole. See also 2 Kings 21:10-15 and 2 Kings 23:26-27.
According to 2 Chronicles 36:21 and Leviticus 26:34, the Babylonian Exile was instead God’s punishment upon the nation for its failure to observe the requirements of the Sabbath Year.
Tradition ascribes 1 and 2 Samuel and 1 and 2 Kings to Jeremiah, and I agree. He portrays Manasseh as, as evil kings go, the worst of the worst. He was the enemy of the prophets. 2 Kings 21:16: “Moreover, Manasseh shed very much innocent blood, until he had filled Jerusalem from one end to another, besides the sin that he caused Judah to sin so that they did what was evil in the sight of the Lord.” I will never understand how God allowed this monster to reign for fifty years; that was, however, also the length of the Exile.
Tradition ascribes 1 and 2 Chronicles to Ezra, and I agree. His portrait of Manasseh is diametric from that of Jeremiah; 2 Chronicles 33:1-20 portrays him as actually a pretty nice guy. And chummy with the priests.
Leviticus 26:34 as written would appear to predict something identical to the Babylonian Exile as penalty for failure to observe the Sabbath Year. However, the “Documentary Hypothesis,” also called “JEDP,” holds that Leviticus was written after the Babylonian Exile, not before.