Because they have committed villany... — The Hebrew noun is almost always used for sins of impurity. It is more commonly rendered “folly” (comp. Genesis 34:7; Deuteronomy 22:21; Judges 19:23-24). The English word “villainy” is used definitely with this meaning by Bishop Hall (Sat. i. 9).
Even I know, and am a witness, saith the Lord. — The words find an echo in Malachi 3:5. We are left to conjecture whether the prophet refers his own knowledge of the facts to a direct supernatural source, or had received private information from his friends at Babylon. The special stress laid on the Lord’s knowledge of their guilt suggests the thought that the false prophets with their restricted ideas of God had persuaded themselves that Jehovah the God of Israel hardly exercised his attributes of power in a distant place like Babylon. There they might sin without fear of detection or of punishment. They thought of him as a God not nigh at hand, but far off (Jeremiah 23:23).