John Trapp on Jeremiah 23:31

Ver. 31. That uſe their tongues] Or abuſe them rather, to ſmoothing and ſoothing up people in their ſins: lenificant linguas, id eſt, blando ſermone alliciunt plebem, they flatter and collogue: or tollunt linguam, they ſift up their tongues, viz. by extolling themſelves, and ſpeaking magnifically of their own doing. As one hath obſerved of ſome Sectaries amongſt us, that they often call upon their hearers to mark; Dulcorantium, mollificantium. Falſe Prophets ſooth & ſweeten men. for it may be they ſhall hear that which they never heard before: When the thing is either falſe, or if true, no more then is ordinarily taught by others, and which they have ſtolen out of the writings of others.

And ſay, He ſaith] See on ver. 30.