Jeremiah 23:31

31 Yes,” declares the LORD, “I am against the prophets who wag their own tongues and yet declare, ‘The LORD declares.’

Read Jeremiah 23:31 Using Other Translations

Behold, I am against the prophets, saith the LORD, that use their tongues, and say, He saith.
Behold, I am against the prophets, declares the LORD, who use their tongues and declare, 'declares the LORD.'
I am against these smooth-tongued prophets who say, ‘This prophecy is from the LORD !’

What does Jeremiah 23:31 mean?

John Gill's Exposition of the Bible
Jeremiah 23:31

Behold, I [am] against the prophets, saith the Lord
Not another sort of prophets distinct from the former, or those that follow; but the same under another character, and against whom he was, and set his face on another occasion; that use their tongues;
at their pleasure, their lips being their own. So the Targum,

``who prophesy according to the will of their own hearts;''
talk in a haughty and insolent manner, speaking bold and daring things of the divine Being; or in a boasting bragging manner, extolling themselves, and speaking highly in their own commendations; or rather in a flattering way to the people: so some read it, by a transposition of a radical letter F18, "that smooth their tongues", as Kimchi; or speak smooth things with their tongues, to please the people: and say, he saith;
that is, "the Lord", as the Vulgate Latin and Syriac versions express it; that so they, night be the more easily believed by the people; but this was highly provoking to God, to father their lies and falsehoods upon him.
FOOTNOTES:

F18 (Myxqwlh) "hic pro" (Myqylxmh) "qui lenificant linguam suam", Pagninus, Gataker; "sumentes blandam linguan suam", Schmidt.
California - Do Not Sell My Personal Information  California - CCPA Notice