Jeremiah 9:7,8

Behold, I will melt them and try them I will cast them into the furnace of affliction, that I may purify them from their dross. See note on Jeremiah 6:29, and on Isaiah 1:25. For how shall I do, &c. I have tried all other means, and they have proved ineffectual. Their tongue is as an arrow, &c. It was compared to a bow bent, Jeremiah 9:3, plotting and preparing mischief; here it is an arrow shot out, putting in execution what they had projected. Dr. Waterland renders the words, as a sharp, or killing arrow; it speaketh deceit They speak what they do not mean, that they may more easily deceive the credulous: they speak fair when they mean to destroy, as the next words explain it.