Jeremiah 28:9

28:9 So if a prophet prophesied ¹  peace and prosperity, it was only known that the Lord truly sent him when what he prophesied came true.”

Jeremiah 23:26

23:26 Those prophets are just prophesying lies. They are prophesying the delusions of their own minds. ² 

Jeremiah 28:10

28:10 The prophet Hananiah then took the yoke off the prophet Jeremiah’s neck and broke it.

[28:9]  ¹ tn The verbs in this verse are to be interpreted as iterative imperfects in past time rather than as futures because of the explicit contrast that is drawn in the two verses by the emphatic syntactical construction of the two verses. Both verses begin with a casus pendens construction to throw the two verses into contrast: Heb “The prophets who were before me and you from ancient times, they prophesied…The prophet who prophesied peace, when the word of that prophet came true, that prophet was known that the Lord truly sent him.”

[23:26]  ² sn See the parallel passage in Jer 14:13-15.