Way before Jesus came to earth and uttered his famous rejection of the Jews, there were pronouncements (denunciations) against faithless Israel that happened repeatedly throughout their history. Jeremiah was commissioned by Jehovah to speak "the word of Jehovah" to the wayward Israelites. Here is just a few examples:
Jer.7:3, 4 This is what Jehovah of armies, the God of Israel, says: Reform your ways and your actions, and I will allow you to keep residing in this place. Do not put your trust in deceptive words and say, ‘This is the temple of Jehovah, the temple of Jehovah, the temple of Jehovah!’
Jer.8:5 Why is this people, Jerusalem, unfaithful with an enduring unfaithfulness? They hold fast to deception; they refuse to turn back.
Jer.8:8 How can you say: “We are wise, and we have the law of Jehovah”? For in fact, the lying stylus of the scribes has been used only for falsehood.
Jer.9:26 "all the nations are uncircumcised, and all the house of Israel are uncircumcised in heart.”
In verse 3, we discover that this was not merely Jeremiah’s words of disapproval, it was the God of Israel severely reproving Israel’s false, self-comforting, rationalizations. It was clear from the above that the Israelites were using both the Temple and the Law as talismans, or good-luck charms. They felt that by having the Temple and the Law, they could do no wrong, nor would God do anything but bless them. In Jer.7:4, Jehovah point-blank tells the Jews that they are only deceiving themselves by claiming the Temple means automatic approval and protection. The collective sin and refusal to change demonstrated who they really were. As far as Jehovah was concerned, "all the house of Israel are uncircumcised in heart." That is, they were spiritually unclean, which was just as objectionable as being physically unclean, which means they had no advantage over the other “nations” they so sneeringly degraded.
Today, in our era, the “Oral Law” seems to have supplanted the “Written Law” so much so, that Jeremiah 8:8 is still true, “the lying stylus of the scribes has been used only for falsehood” in claiming God’s approval.