The pen of the scribes is in vain - The deceitful pen of the scribes. They have written falsely, though they had the truth before them. It is too bold an assertion to say that "the Jews have never falsified the sacred oracles;" they have done it again and again. They have written falsities when they knew they were such.
The law of the Lord - The “Torah,” or written law, the possession of which made the priests and prophets so boastfully exclaim, “We are wise.”
Lo, certainly - Rather, Verily, lo! the lying pen “of the scribes” hath made it - the Law - into a lie. The mention of “scribes” in this place is a crucial point in the argument whether or not the Pentateuch or Torah is the old law-book of the Jews, or a fabrication which gradually grew up, but was not received as authoritative until after the return from the captivity. It is not until the time of Josiah 2 Chronicles 34:13 that “scribes” are mentioned except as political officers; here, however, they are students of the Torah. The Torah must have existed in writing before there could have been an order of men whose special business it was to study it; and therefore to explain this verse by saying that perhaps the scribes were writers of false prophecies written in imitation of the true, is to lose the whole gist of the passage. What the scribes turned into a lie was that Law of which they had just boasted that they were the possessors. Moreover, the scribes undeniably became possessed of preponderating influence during the exile: and on the return from Babylon were powerful enough to prevent the restoration of the kingly office. That there should be along with the priests and Levites men who devoted themselves to the study of the written Law, and who in the time of Josiah had acquired such influence as to be recognized as a distinct class - is just what we should expect from the rapid progress of learning, which began with Elisha‘s active management of the schools of the prophets, and culminated in the days of Hezekiah. Jeremiah‘s whole argument depends upon the fact that there were in his days men who claimed to be “wise” or “learned” men because of their study of the Pentateuch, and is entirely inconsistent with the assumptions that Jeremiah wrote the book of Deuteronomy, and that Ezra wrote parts of Exodus and the whole of Leviticus.