Jeremiah 31:11 - Matthew Poole's English Annotations on the Holy Bible

Because of the certainty of Divine prophecies and promises, things in them are often said to be already done which are not to be fulfilled of many years after. The sense is, God will as certainly do it as if he had already done it; for whether it be understood of a deliverance from Babylon, or of the salvation of the gospel by Christ, which by a metaphor is often also called redeeming and ransoming, it was to be accomplished long after this time. By him that was stronger than he, some understand the Chaldeans, others understand the devil (interpreting the text of the spiritual redemption of God's people by the blood of Christ, being the ransom given for them); but undoubtedly the text is literally to be understood of their deliverance from Babylon, though (as the apostle saith) all these things happened to them in a figure. In their deliverance, as well from Babylon as Egypt, they were types of the deliverance of God's people from spiritual Babylon and Egypt by Christ, as well as in their entering into Canaan they were (as the apostle proveth, Heb 3 Heb 4) types of the saints entering into heaven, of which Canaan was a type.