The Lord introduces a period of seventy into his word of judgment against Judah and the nations by saying, These nations shall serve the king of Babylon seventy years.
Many commentators have attempted to identify the seventy years with a precise period but none of these attempts are fully successful.1 There is certainly nothing in the text that identifies an exact period.
The ”seventy years” does refer to the approximate time between some very important historical events that took place around Judah’s exile to Babylon and return to the land. But it seems that the reason for mentioning the period here is not so that the reader or listener can identify what specific period is spoken of, but rather to make it clear that it is a significantly long period of time. The theme of Jeremiah 25:1–38 is the Lord’s universal judgment of the world and there is no mention of hope or restoration. So, in that context there is no need to see the seventy years as a hint of hope. Seventy years refers to a normal lifespan (Psalm 90:10) and so the impact in this context is that those who face the Lord’s judgment through the Babylonian invasion and subjugation will probably not live to see the end of it.
Later reflection by others on Jeremiah's mentioning of seventy years leads to it taking on theological importance (2 Chronicles 36:20–23; Daniel 9:2; Ezra 1:1; Zechariah 1:12).2 In these reflections the seventy-year period takes on a more positive meaning because it means that as devastating as the Lord’s judgment is, it will not be the end of his dealings with Judah, or the world. But there is no indication that seventy years is a sign of hope in Jeremiah 25:1–38.
11 This whole land shall become a ruin and a waste, and these nations shall serve the king of Babylon seventy years.