Thomas Aquinas Commentary Jeremiah 8:8-9

"How do ye say, We are wise, and the law of Jehovah is with us? But, behold, the false pen of the scribes hath wrought falsely. The wise men are put to shame, they are dismayed and taken: lo, they have rejected the word of Jehovah; and what manner of wisdom is in them?" — Jeremiah 8:8-9 (ASV)

Here, he shows their pride, which stems from their boast of wisdom; concerning this, there are three things.

1. He speaks of their boast: we are wise. Woe to you, who are wise in your own eyes, and prudent in your own estimation (Isaiah 5:21).
2. He shows their injustice: when the lying pen of the scribes has worked falsehood, either by wrongly interpreting the Scriptures or by establishing wicked laws. Woe to those who establish wicked laws, and when they write, have written injustice to oppress the poor in judgment, and do violence to the cause of the humble of my people (Isaiah 10:1).
3. He speaks of their punishment: the wise are confounded—taking the past tense for the future. He brings counselors to a foolish end, and judges to astonishment (Job 12:17).

Then, he resumes his case: they have cast aside the word of the Lord. The word of the Lord in the highest is a wellspring of wisdom . Therefore are my people led captive, for they had not knowledge (Isaiah 5:13). Because you rejected wisdom, I will reject you from being a priest before me (Hosea 4:6).